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KrashanTopolova
02-17-2006, 05:21 PM
They believe a plane can take off from a conveyor belt... http://forums.ubi.com/images/smilies/88.gif

See Interesting Puzzle Discussion: http://forums.ubi.com/images/smilies/disagree.gif
They don't understand physics...to wit: they couldn't understand when I said that according to Newton's Laws of motion an accelerating body will continue accelerating in space (disregarding forces such as bombardment with atomic particles as it accelerates through a vacuum of space)...all the while not understanding that they themselves along with the rest of us are accelerating into a black hole at the centre of the this galaxy...simply from F=ma <=> a=F/m (Where F = the black hole sucker)

They descend into verbal nonsense as defence of their idea that planes can fly from conveyor belts...


However, they have never proved their theory.
They have never shown WHERE the aircraft purportedly rotates into flight (is it on or off the conveyor belt as in off a conveyor belt near a cliff or front end of an aircraft carrier which then gives the aircraft some room to climb ? etc.).
They have never shown WHEN the aircraft purportedly rotates into flight...They have never shown HOW it lifts off with no movement of the wings to gain airspeed relative to the rrelevant fixed point in space...the mass of air surrounding the aircraft which it needs to accompish flight...

So:
Another perspective as to why a conventional aircraft will not take off from a conveyor belt:

There are many physics perspectives from which to come at this physics question. For example you could view it simply as an energy problem (even though the conveyor belt flyers don't easily tolerate that energy can be transformed by or within a machine)...

Or you could look at it from a forces perpective.

Much of the argument from the conveyor belt flyers centres on disputing that the wheels of the aircraft have anything to do with its ability to proceed to flight. They state that the wheels of the aircraft in contact with the conveyor belt will spin faster than if in contact with a non-moving runway. Yet there is no acknowledgement from them that kinetic energy is intimately connected to the wheels of the aircraft.
(in fact the wheels are turned by a force at their rim which makes a larger force at the axle of the wheel). The conveyor purportedly keeps proportional pace with the rotation rate of the wheels but they don't recognise that the kinetic energy in the wheels will have to be released as heat and destruction of the wheels because the transformation of that energy into the energy of flight is denied by the conveyor (remembering that energy can only be conserved and changed not destroyed).
In fact the wheels of the aircraft are turning with a smaller force than the moment of the conveyor belt...this is simple gear ratio in operation. But it is illusory to suggest that this can catapult the aircraft into the air.

They insist a car acts differently on the conveyor belt but this is an illusion. They obviously assume that a car has a direct moment arm in contact with the wheels in contact with the conveyor (driveshaft axle)...
However, an aircraft appears to them to have an indirect moment arm on the conveyor (propellor thrust)...and it is this they exclaim that is the pivotal difference which makes an aircraft fly off a conveyor belt stationary to fixed space...

I however, assert that the aircraft - whatever moment arm of the force - is in equilibrium with all forces and thus it remains stationary to a fixed point in space while on the conveyor belt and will remain in equilibrium on the conveyor belt...and NOT TAKE OFF...

This is so because the Resultant (combination of all forces acting on the aircraft cancel each other out and thus no overall force is acting on the aircraft to make it move from a constant speed or to stop it from remaining stationary to a fixed point in space while it is on the conveyor belt...

The aircraft in fact has Terminal Velocity because all forces are exactly matched to create a constant speed of the airfoil...which on the conveyor belt is zero relative to a fixed point in space away from the conveyor belt...thus there is no lift...and that is the crux...without an airfoil developing lift from airflow the final force (lift) does not come into existence to counter gravity...

thus the only mechanism remaining to them to accomplish liftoff is the power of the propellor...which if it is not pointing upward has no hope of lifting the aircraft off the conveyor belt... http://forums.ubi.com/images/smilies/88.gif


Conveyor belt flyers are locked into a square and cannot think outside of it...never choose one as your wingman...

Chuck_Older
02-17-2006, 05:27 PM
I bet you feel better, now that this is off your chest

BaldieJr
02-17-2006, 05:35 PM
Bearing.Preload.

Chuck_Older
02-17-2006, 05:39 PM
It's all ball bearings, nowadays

Texan...
02-17-2006, 05:42 PM
Now I want you to prepare that fetzer valve with some gauze pads and 3-in-1 oil.

http://skyjude.users.btopenworld.com/fletchuk/Images/1fletchlives4.jpg

icrash
02-17-2006, 05:44 PM
Good lord, put it in idiot for me please. This looks like something you'd get if you ask Chris Carmichael why Lance Armstrong is fast http://forums.ubi.com/images/smilies/blink.gif

Chuck_Older
02-17-2006, 05:45 PM
Originally posted by icrash:
Good lord, put it in idiot for me please. This looks like something you'd get if you ask Chris Carmichael why Lance Armstrong is fast http://forums.ubi.com/images/smilies/blink.gif

OK http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

"Plane no fly"

DaimonSyrius
02-17-2006, 06:01 PM
Originally posted by BaldieJr:
Bearing.Preload.

Certainly. And sounds from falling tress, let's not skip that over.

Cheers,
S.

tjaika1910
02-17-2006, 06:08 PM
Originally posted by KrashanTopolova:
They believe a plane can take off from a conveyor belt... http://forums.ubi.com/images/smilies/88.gif

See Interesting Puzzle Discussion: http://forums.ubi.com/images/smilies/disagree.gif
They don't understand physics...to wit: they couldn't understand when I said that according to Newton's Laws of motion an accelerating body will continue accelerating in space (disregarding forces such as bombardment with atomic particles as it accelerates through a vacuum of space)...all the while not understanding that they themselves along with the rest of us are accelerating into a black hole at the centre of the this galaxy...simply from F=ma <=> a=F/m (Where F = the black hole sucker)

They descend into verbal nonsense as defence of their idea that planes can fly from conveyor belts...


However, they have never proved their theory.
They have never shown WHERE the aircraft purportedly rotates into flight (is it on or off the conveyor belt as in off a conveyor belt near a cliff or front end of an aircraft carrier which then gives the aircraft some room to climb ? etc.).
They have never shown WHEN the aircraft purportedly rotates into flight...They have never shown HOW it lifts off with no movement of the wings to gain airspeed relative to the rrelevant fixed point in space...the mass of air surrounding the aircraft which it needs to accompish flight...

So:
Another perspective as to why a conventional aircraft will not take off from a conveyor belt:

There are many physics perspectives from which to come at this physics question. For example you could view it simply as an energy problem (even though the conveyor belt flyers don't easily tolerate that energy can be transformed by or within a machine)...

Or you could look at it from a forces perpective.

Much of the argument from the conveyor belt flyers centres on disputing that the wheels of the aircraft have anything to do with its ability to proceed to flight. They state that the wheels of the aircraft in contact with the conveyor belt will spin faster than if in contact with a non-moving runway. Yet there is no acknowledgement from them that kinetic energy is intimately connected to the wheels of the aircraft.
(in fact the wheels are turned by a force at their rim which makes a larger force at the axle of the wheel). The conveyor purportedly keeps proportional pace with the rotation rate of the wheels but they don't recognise that the kinetic energy in the wheels will have to be released as heat and destruction of the wheels because the transformation of that energy into the energy of flight is denied by the conveyor (remembering that energy can only be conserved and changed not destroyed).
In fact the wheels of the aircraft are turning with a smaller force than the moment of the conveyor belt...this is simple gear ratio in operation. But it is illusory to suggest that this can catapult the aircraft into the air.

They insist a car acts differently on the conveyor belt but this is an illusion. They obviously assume that a car has a direct moment arm in contact with the wheels in contact with the conveyor (driveshaft axle)...
However, an aircraft appears to them to have an indirect moment arm on the conveyor (propellor thrust)...and it is this they exclaim that is the pivotal difference which makes an aircraft fly off a conveyor belt stationary to fixed space...

I however, assert that the aircraft - whatever moment arm of the force - is in equilibrium with all forces and thus it remains stationary to a fixed point in space while on the conveyor belt and will remain in equilibrium on the conveyor belt...and NOT TAKE OFF...

This is so because the Resultant (combination of all forces acting on the aircraft cancel each other out and thus no overall force is acting on the aircraft to make it move from a constant speed or to stop it from remaining stationary to a fixed point in space while it is on the conveyor belt...

The aircraft in fact has Terminal Velocity because all forces are exactly matched to create a constant speed of the airfoil...which on the conveyor belt is zero relative to a fixed point in space away from the conveyor belt...thus there is no lift...and that is the crux...without an airfoil developing lift from airflow the final force (lift) does not come into existence to counter gravity...

thus the only mechanism remaining to them to accomplish liftoff is the power of the propellor...which if it is not pointing upward has no hope of lifting the aircraft off the conveyor belt... http://forums.ubi.com/images/smilies/88.gif


Conveyor belt flyers are locked into a square and cannot think outside of it...never choose one as your wingman...

Well, I know physics and I gave the answer on the first page of the thread (thinking that would be the end of that puzzle http://forums.ubi.com/images/smilies/35.gif)

The plane will take off, the belt would make the wheels spin twice as fast.

But one ... whats the english word... assumption is that the belt tries to emulate the speed of the plane. If the belt tries to emulate the speed of the wheels it would certainly go faster then twice as fast. It would soon collapse, but if made perfect (non-breakable) you would end up in a situation that the propellor force would equal the torqe and restistance of the wheel. If they also were unbreakable the plane would stand still, some 10000 or 100000 rpm on the wheel and a enormous speed on the belt (which was unbreakable http://forums.ubi.com/images/smilies/53.gif)

But still the plane would take off (Krashan http://forums.ubi.com/groupee_common/emoticons/icon_mad.gif) Because the belt would make an enourmous wind and thus give lift to the wings...

Qed (again http://forums.ubi.com/images/smilies/11.gif)

icrash
02-17-2006, 06:15 PM
Originally posted by Chuck_Older:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by icrash:
Good lord, put it in idiot for me please. This looks like something you'd get if you ask Chris Carmichael why Lance Armstrong is fast http://forums.ubi.com/images/smilies/blink.gif

OK http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

"Plane no fly" </div></BLOCKQUOTE>

Thanks, that makes far more sense to this redneck Texan http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Chuck_Older
02-17-2006, 06:15 PM
you're no fun anymore

danjama
02-17-2006, 06:16 PM
Youd need a pretty long and wide conveyor belt for an airplane to takeoff of it

slo_one23
02-17-2006, 06:22 PM
screw the conveyor belt i think better idea would be throw the plane of a clif an

Chuck_Older
02-17-2006, 06:26 PM
an what?

TX-EcoDragon
02-17-2006, 06:28 PM
RBJ?

The-Pizza-Man
02-17-2006, 06:32 PM
I've seen this stupid question asked before. If it the one with "will a plane take off from a conveyer belt if it matches it's speed but in reverse?".

The answer is that yes, the plane will take off. The wheels of the plane will be spinning at twice the normal rate when it rotates but it will have almost no other effect.

Say the plane starts moving forward at 20 knots, so the conveyer belt matchs that speed and goes 20 knots in reverse. It spins the wheels of the plane but no force is actually transfered to the plane other than a small amount of friction in the bearings. Thus the plane continues to move forward in relation to the ground.

The bottom line is that the conveyer belt exerts no force on the plane except for a small amount of friction at the wheel bearings but the plane still exerts force on the on the air, which is independent of the conveyer belt. Thus the plane still accelerates just fine and still takes off.

If you want the plane to remain stationary you have to give it a headwind that matches it's forward speed, but even then the plane will still take off but it will just hover like a helicopter when it does.

danjama
02-17-2006, 06:34 PM
Originally posted by The-Pizza-Man:
I've seen this stupid question asked before. If it the one with "will a plane take off from a conveyer belt if it matches it's speed but in reverse?".

The answer is that yes, the plane will take off. The wheels of the plane will be spinning at twice the normal rate when it rotates but it will have almost no other effect.

Say the plane starts moving forward at 20 knots, so the conveyer belt matchs that speed and goes 20 knots in reverse. It spins the wheels of the plane but no force is actually transfered to the plane other than a small amount of friction in the bearings. Thus the plane continues to move forward in relation to the ground.

The bottom line is that the conveyer belt exerts no force on the plane except for a small amount of friction at the wheel bearings but the plane still exerts force on the on the air, which is independent of the conveyer belt. Thus the plane still accelerates just fine and still takes off.

If you want the plane to remain stationary you have to give it a headwind that matches it's forward speed, but even then the plane will still take off but it will just hover like a helicopter when it does.

go ahead and spoil a good thread http://forums.ubi.com/images/smilies/51.gif

Chuck_Older
02-17-2006, 06:34 PM
Just when I thought the boards were like the old ORR again, fact and reason ruins a perfectly silly thread

DaimonSyrius
02-17-2006, 06:58 PM
Originally posted by icrash
I've always wondered if Crazy Ivan actually reads down this far and if he's really crazy.
Wouldn't the former actually imply the latter?

http://forums.ubi.com/images/smilies/winky.gif

Cheers,
S.

Treetop64
02-17-2006, 07:25 PM
Yeah, that's rich, Krashan...

...Mods lock the previous thread. So you bulldoze in to start a new one. http://forums.ubi.com/images/smilies/51.gif

That's classy. I'm impressed... http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

Chuck_Older
02-17-2006, 07:40 PM
Well, so far we're not letting it become a success http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

arjisme
02-17-2006, 07:53 PM
Ya'll hush now. A pilot is speaking! http://forums.ubi.com/images/smilies/winky.gif

Davinci..
02-17-2006, 07:58 PM
You are wrong..
you were wrong before, you are wrong now.
you dont know Newtons laws, you dont know what they mean, you do not understand the physics behind motion, or anything else for that matter.
You are not a pilot, and do not know/understand the principles of flight. you dont know the difference between ground speed and airspeed.

We all know it, and you do to..

Mods please lock this and ban this person..

Trolling should be a bannable offence.. He has contributed nothing to this community, other then continually spout off the complete opposite of that which is true..

especially when the mods locked the thread(and rightly so), and he just started a new one to do the same thing again..

lock this, and ban him. i see no reason not to..

danjama
02-17-2006, 07:59 PM
Originally posted by Davinci..:
You are wrong..
you were wrong before, you are wrong now.
you dont know Newtons laws, you dont know what they mean, you do not understand the physics behind motion, or anything else for that matter.
You are not a pilot, and do not know/understand the principles of flight. you dont know the difference between ground speed and airspeed.

We all know it, and you do to..

Mods please lock this and ban this person..

Trolling should be a bannable offence.. He has contributed nothing to this community, other then continually spout off the complete opposite of that which is true..

especially when the mods locked the thread(and rightly so), and he just started a new one to do the same thing again..

lock this, and ban him. i see no reason not to..

chill

Akronnick
02-17-2006, 08:14 PM
BHOD(Banging head on desk)

my head hurts.

DaimonSyrius
02-17-2006, 08:30 PM
Originally posted by Davinci..:
He has contributed nothing to this community

Beg to differ here... The laughs inspired, kindly provided to all, are a valuable asset in today's stressful world.

http://forums.ubi.com/images/smilies/halo.gif

Cheers,
S.

P.S.: Hey, I can say 'asset' ! http://forums.ubi.com/images/smilies/winky.gif

Davinci..
02-17-2006, 08:34 PM
Originally posted by DaimonSyrius:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Davinci..:
He has contributed nothing to this community

Beg to differ here... The laughs inspired, kindly provided to all, are a valuable asset in today's stressful world.

http://forums.ubi.com/images/smilies/halo.gif

Cheers,
S.

P.S.: Hey, I can say 'asset' ! http://forums.ubi.com/images/smilies/winky.gif </div></BLOCKQUOTE>

heh, i guess.. but were laughing at him not with him. And i feel bad about it, its like laughing at a special olympian.

DaimonSyrius
02-17-2006, 08:37 PM
Originally posted by Davinci..:
its like laughing at a special olympian.
http://forums.ubi.com/images/smilies/51.gif

He's coming here by his own will, so we're all (including him) having good fun http://forums.ubi.com/images/smilies/partyhat.gif

Cheers,
S.

DaimonSyrius
02-17-2006, 08:46 PM
...Do I (fail to) hear distant trees falling down...?

*hint*hint* *wink*wink* *nudge*nudge*

Cheers,
S.

Targ
02-17-2006, 09:02 PM
Lol, you guys are funny http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif
Amazing what people can get worked up over isnt it?

danjama
02-17-2006, 09:46 PM
Originally posted by Targ:
Lol, you guys are funny http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif
Amazing what people can get worked up over isnt it?

http://forums.ubi.com/images/smilies/metal.gif

Gold_Monkey
02-17-2006, 09:52 PM
You are not a pilot, and do not know/understand the principles of flight. you dont know the difference between ground speed and airspeed.

I am, I do, I know http://forums.ubi.com/images/smilies/metal.gif Veni, Vidi, Vici.

jimDG
02-17-2006, 10:03 PM
A certain head of state leans against a wall after a work-out. Thw wall collapses. Why? The smarter yields first.

DaimonSyrius
02-17-2006, 10:31 PM
Alright, since it's that late boring time again...

A falling tree in a forest will always cause cyclic fluctuations in air pressure, but 'sound' will only occur when there is a sentient being around to actually hear it. While air will vibrate no matter what, sound as such is a perceptual phenomenon that only takes place from the inner ear inwards. That's according to my interpretation of reality, of course.

Now... what would happen if there were only a recording device (such as a magnetophone, switched on) around when the tree fell? Would it be collecting and recording sound at all?

Cheers,
S.

LStarosta
02-17-2006, 10:55 PM
Originally posted by Davinci..:
You are wrong..
you were wrong before, you are wrong now.
you dont know Newtons laws, you dont know what they mean, you do not understand the physics behind motion, or anything else for that matter.
You are not a pilot, and do not know/understand the principles of flight. you dont know the difference between ground speed and airspeed.



Tom? Tom Cruise? Is that you in there? Why won't you come out of the closet? http://forums.ubi.com/images/smilies/blink.gif

Davinci..
02-17-2006, 10:57 PM
Originally posted by LStarosta:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Davinci..:
You are wrong..
you were wrong before, you are wrong now.
you dont know Newtons laws, you dont know what they mean, you do not understand the physics behind motion, or anything else for that matter.
You are not a pilot, and do not know/understand the principles of flight. you dont know the difference between ground speed and airspeed.



Tom? Tom Cruise? Is that you in there? Why won't you come out of the closet? http://forums.ubi.com/images/smilies/blink.gif </div></BLOCKQUOTE>

my publicist wont let me out http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

Akronnick
02-18-2006, 01:12 AM
Originally posted by DaimonSyrius:
Alright, since it's that late boring time again...

A falling tree in a forest will always cause cyclic fluctuations in air pressure, but 'sound' will only occur when there is a sentient being around to actually hear it. While air will vibrate no matter what, sound as such is a perceptual phenomenon that only takes place from the inner ear inwards. That's according to my interpretation of reality, of course.

Now... what would happen if there were only a recording device (such as a magnetophone, switched on) around when the tree fell? Would it be collecting and recording sound at all?

Cheers,
S.

If the tree falls on the airplane while it's trying to take off, will his lawyer sue Oleg for copyright infringement?

quasimodo_3
02-18-2006, 01:31 AM
as if the wheels ever had anything to do with it...

ATLAS_DEATH
02-18-2006, 01:33 AM
pfft... what do you think free spinnin wheels are for... come on now.. the plane will fly.. you can do this at home.. get a "conveyor belt" and a free spinning wheel with something to hold.. such as..a wheel off your office chair... hold it on the belt.. ok it's spinning... now move the wheel against the belt.. hey look... you could move it... interesting... you don't need a degree to understand that.. planes are not cars!

arjisme
02-18-2006, 07:46 AM
Originally posted by ATLAS_DEATH:
pfft... what do you think free spinnin wheels are for... come on now.. the plane will fly.. you can do this at home.. get a "conveyor belt" and a free spinning wheel with something to hold.. such as..a wheel off your office chair... hold it on the belt.. ok it's spinning... now move the wheel against the belt.. hey look... you could move it... interesting... you don't need a degree to understand that.. planes are not cars! You forgot to factor in induced drag of conveyor, moment arms, calculus of inertia, Newton's laws 1-3, Einstein, and a few other scientific words. It won't move.

Dash_C.
02-18-2006, 07:56 AM
Originally posted by slo_one23:
screw the conveyor belt i think better idea would be throw the plane of a clif an

Good Lord! He's been abducted by aliens again!

danjama
02-18-2006, 09:39 AM
get over this conveyor belt **** its boring the hell out of me

bun-bun195333
02-18-2006, 10:02 AM
//home.comcast.net/~argylestransom/Pics/Fries.jpg

rnzoli
02-18-2006, 03:42 PM
http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif I couldn't believe my eyes that he started another thread only to advertise his stupidity. Well done! http://forums.ubi.com/images/smilies/clap.gif


Now since all this mess is georgo76's fault, I kindly invite him to post a p0rn pic, preferably something spicy with a conveyor. This topic should be locked, too.

It doesn't matter whether the plane flies or not. There are no conveyor belts in Forgotten Battles http://forums.ubi.com/images/smilies/59.gif

KrashanTopolova
02-19-2006, 04:11 PM
Originally posted by The-Pizza-Man:
I've seen this stupid question asked before. If it the one with "will a plane take off from a conveyer belt if it matches it's speed but in reverse?".

The answer is that yes, the plane will take off. The wheels of the plane will be spinning at twice the normal rate when it rotates but it will have almost no other effect.

Say the plane starts moving forward at 20 knots, so the conveyer belt matchs that speed and goes 20 knots in reverse. It spins the wheels of the plane but no force is actually transfered to the plane other than a small amount of friction in the bearings. Thus the plane continues to move forward in relation to the ground.
___________________________________________
not if the everything is free-running
-------------------------------------------

The bottom line is that the conveyer belt exerts no force on the plane except for a small amount of friction at the wheel bearings but the plane still exerts force on the on the air, which is independent of the conveyer belt. Thus the plane still accelerates just fine and still takes off.

If you want the plane to remain stationary you have to give it a headwind that matches it's forward speed, but even then the plane will still take off but it will just hover like a helicopter when it does.

______________________________________________
Nice try...but you cannot start at any speed above v=0

Think of it this way:
place a mark on the conveyor belt in alignment with another mark painted on both wheels of the aircraft sitting on the conveyor belt...


Now:
if after one revolution of the conveyor belt, the aircraft wheel will have done (say) 500 revs to that one rev of the conveyor belt...

Now:
if the marks line up perfectly after that one conveyor belt revolution then the aircraft is in equilibrium with all forces acting on it and it will remain in equilibrium On The Conveyor Belt at any further faster rate of revolution because it is the free-running wheels of the aircraft that determine the rate of revolution of the conveyor belt and hence a terminal velocity.


Conversely:
If the marks do not align after one revolution then one or more forces are not in equilibrium and the aircraft will obey those forces...which include the possibility that the aircraft will move forward on the conveyor belt (where would the aircraft wheel mark be in relation to the conveyor belt mark in that case?) ...
Nevertheless the conveyor would need to be extremely long to equal the potential of a non-moving runway in developing airspeed for liftoff...
But this possibility need not be considered since it does not arise in this system which is a system in equilibrium...the aircraft will not liftoff without there being a possibility of gaining airfoil speed through the associated air mass which it does not...
nor can it any time hover like a helicopter unless lift exceeds the Resultant from a headwind that exceeds the thrust (thus an aircraft can fly backwards).
______________________________________________

Cajun76
02-19-2006, 04:42 PM
What if the wheel brakes were locked, but the a/c was on slippery ice, virtually friction free?

Do the wheels make a difference to the thrust of the engine?

Lift opposes gravity.

Thrust opposes drag (which is friction in various forms).

Do free spinning wheels create as much drag as a a/c engine?

It's a trick question, and I was tricked myself. Once one looks objectively at the forces involved, they'll understand. Good luck and

Popey109
02-19-2006, 05:27 PM
Well, unless you move the wing, or move air over the wing it ain't going anywhere...is it?

Xiolablu3
02-19-2006, 05:47 PM
Lol is this guy for real?

It took me a couple of tries to understand it, but by the 4th page of the thread I was there http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif


The speed the wheels turns makes NO difference to the forward movement of the plane!!

The propeller drags the plane forward using the air, the wheels can keep spinng backwards as much as they like but they arent going to stop the propellor pulling the plane forward!

The plane still needs a conveyer belt as long as its normal take off run to take off.

Get it now? (I am pretty sure after the amount of times it was explained before that you must be trolling)

p-11.cAce
02-19-2006, 05:56 PM
ok to change the dynamic a bit (and maybe open some eyes) lets say the conveyor belt is covered in teflon and instead of wheels the plane is ski equipped - lots of aircraft use skis instead of wheels. Ok so the conveyor belt is spinning away under the aircraft which just throttles up and takes off. The takeoff run may be increased somewhat due to the added friction caused by the speed of the conveyor belt - does the friction coefficent of a surface increase with speed? I'm not sure. Anyway the point is the airplane takes off.

KrashanTopolova
02-19-2006, 06:13 PM
Originally posted by Popey109:
Well, unless you move the wing, or move air over the wing it ain't going anywhere...is it?

_________________________
Well done...!
_________________________

p-11.cAce
02-19-2006, 06:18 PM
I have yet to understand what it is that keeps the airplane from moving fwd??? This is so inane as to defy belief.

KrashanTopolova
02-19-2006, 06:26 PM
One of the fundamental laws of motion states that the acceleration of an object is directly proportional to the resultant force on it and inversely proportional to its mass...

From this one then has to determine the dimensions of force. When we do that we find that the conveyor belt flyers have one vital dimension missing...Length

hence no acceleration because the aircraft does not proceed any length along the conveyor belt which it has to to have sufficent speed relative to its associated air mass to obtain lift over the airfoil

Here then is the dimensional analysis of force:

mass x length x time to the -2 power

this results in having the units kg . m/s2 which are the only units required in order to express the force acting on the aircraft in Newtons

Since there is no length in the conveyor belt flyer's theory...the aircraft can only be in equilibrium to the forces acting on it.

DaimonSyrius
02-19-2006, 06:35 PM
Originally posted by KrashanTopolova:
no acceleration because the aircraft does not proceed any length along the conveyor belt
Hint: frame of reference (http://en.wikipedia.org/wiki/Frame_of_reference).

The relevant frame of reference regarding an aircraft is *air*, not conveyor belts. Be it at takeoff, during flight, or in landing.

Oh, and: *Yawn*

Cheers,
S.

KrashanTopolova
02-19-2006, 06:43 PM
Originally posted by Xiolablu3:
Lol is this guy for real?

It took me a couple of tries to understand it, but by the 4th page of the thread I was there http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif


The speed the wheels turns makes NO difference to the forward movement of the plane!!
_______________________________________________
there is no forward movement of the aircraft either relative to the conveyor or to the associated air mass in which the conveyor and aircraft exist.
_______________________________________________

The propeller drags the plane forward using the air, the wheels can keep spinng backwards as much as they like but they arent going to stop the propellor pulling the plane forward!
_______________________________________________
There might be whence your confusion turns...the aircraft wheels are not 'spinning backwards'...they are spinning forwards as normal.
The propellor does not 'pull' anything...it does not 'use' air...it screws itself through the air taking along with it anything to which it is attached...in this case an aircraft with airfoils that need an acceleration relative to the air mass in which it exists to obtain and sustain lift
_______________________________________________

The plane still needs a conveyer belt as long as its normal take off run to take off.
_______________________________________________
I would like to know where and when and from what source you guys got this idea
_______________________________________________

Get it now? (I am pretty sure after the amount of times it was explained before that you must be trolling)
_______________________________________________
Poor Krashan! He was a caesarian birth. It didn't affect him, but I noticed he always left the house through the front window.
_______________________________________________

Popey109
02-19-2006, 06:44 PM
Have...to...type fast...trying...to keep...up...with the...planet http://forums.ubi.com/images/smilies/88.gif

elphifou
02-19-2006, 08:43 PM
Did the riddle mention the presence of a hot chick in the cockpit? Temperature around the plane might be critical after all...

I don't know... what d'ya think Krashan ?

(Krashan, you do NOT have to answer my question)

http://forums.ubi.com/images/smilies/35.gif

KrashanTopolova
02-20-2006, 06:20 PM
Originally posted by p-11.cAce:
I have yet to understand what it is that keeps the airplane from moving fwd??? This is so inane as to defy belief.

_____________________________________________
The aircraft does move forward.

consider a propellor plane:

during one 'thrust' of the propellor blade (airfoil) it impels the aircraft attached to it to move forward but this is not enough to overcome the drag forces operating on the aircraft during this singular thrust work and the drag forces reduce the momentum towards zero...but not quite zero (or maybe zero but not under exclusive conditions)...because if it is fast enough the next propellor blade is coming with its thrust potential before the thrust of the first prop blade is diminished entirely...hence there is a minute net force building for forward momentum and acceleration.
All this is better pictured in slow motion. At the high speeds of propellor rotation those minute differences between thrust and drag are magnified into a huge difference of thrust over drag...hence there is acceleration (theoretically even with a one-bladed propellor).
This forward momentum is only possible when the wheels are able to grip a rough non-moving surface because of the gravity in which the aircraft exists which produces weight of aircraft upon the wheels...hence frictional grip.

Now:
whether the plane is being thrust forward by a propellor or jet makes no significant difference to the ability of the aircraft wheels to grip its ground surface whether that surface is moveable or not...this means that the ground surface pushes against the wheels with the same force that the aircraft pushes against the ground. Which means further, that it is the free-running aircraft wheels that determine the rate of movment of any free-running moveable surface on which it stands (such as a conveyor) under the enabling and slightly disabling influences of respectively the gravity vector and the force vectoring forward (the horizontal thrust).

Now:
when the surface on which the aircraft is moving forward is now in fact moving in the same direction as the bottom of the wheels (grip area) under the enabling influence of the aircraft wheels it means that (even though the aircraft wheels still have grip) the forces acting on the aircraft wheels and the aircraft to which they are attached dependantly are different to those from a non-moving surface and those forces result in a net force (net result of the combination of all vector forces) that keeps the aircraft at a terminal velocity (think of a parachutist dropping to earth under the influence of gravity...the air friction on the parachutist's body builds up until it exactly matches in opposition the acceleration which the gravity is producing on the falling body...then acceleration is no more and the body falls with constant velocity or as may be termed: terminal veloity, until the parachutist opens the chute to increase drag and lands safely).

in summary: thrust moves the aircraft wheels and the aircraft wheels in turn move the conveyor belt.

In a reverse way the reverse momentum of the conveyor belt prevents thrust from overcoming drag...and thus equilibrium of forces is produced such that no net force forward relative to a fixed point in space is acting on the aircraft.

The suggestion that the aircraft will reach liftoff speed relative to the air surrounding it depends on the fact that the aircraft wheels Do Not determine the rate of revolution of the conveyor belt...but of course they do.

In contrast to some suggestions made by supporters of the theory for flight from a conveyor belt...the wheels will not turn twice or thrice as fast as normal..they will act as normal under the normal thrust because they act in response to the thrust provided... not to any input from the conveyor belt (which is a system dependant on the rate of rotation of the aircraft wheels).

Now:
Consider if the aircraft were on a conveyor belt that revolved in the same direction as the top of the aircraft wheels...then the aircraft would take off...(if it had sufficient thrust).
____________________________________________
'...flight centre control to captain Murphy...what is your height and position?...this is captain Murphy to control...I'm five feet two and I'm sitting up the front...'

p-11.cAce
02-20-2006, 06:57 PM
http://forums.ubi.com/images/smilies/blink.gif Ok lets make this very simple. You are in wally world and you buy a cheap rubberband powered balsa airplane. You get bored in the checkout lane so you break out your little airplane and wind it up. You don't want to alert the manager by launching towards the door so you decide to play "navy" and launch that sucker off the "carrier" represented in this case by the little conveyor belt. Just as you set the model down on the belt a freak short circuit accelerates the belt to a high speed. You shrug your shoulders and set the model down - its wheel spin up as you hold onto the model - then you let go of the prop, the thrust pulls the aircraft fwd (the wheels rotational speed just matches the speed of the conveyor but is irrelevent) and once the model reaches its critical airspeed it lifts off and flys away. You can try to use fancy terms and big words but anyone who thinks the airplane will not takeoff knows zip zero nada about how an airplane operates.

BaldieJr
02-20-2006, 08:04 PM
show me the naca test datas of this plane that flies from teh supernatural conveyor belt.

its like god. you can bring any proofs. ever.

arjisme
02-20-2006, 08:22 PM
The only thing moving the conveyor is its own motor. The motor moves the conveyor belt backward at the same speed that the plane moves forward. It does not match the rotational speed of the wheels. It matches the forward airspeed of the plane.

KrashanTopolova
02-20-2006, 09:46 PM
What?...so now the conveyor has a motor? http://forums.ubi.com/images/smilies/blink.gif

I don't remember a motor for the conveyor being mentioned in the initial setup...hell that introduces all sorts of new conditions...for example now we find that not only is there a motor putting in N's of force but that it is already in motion... http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

Are you sure you fellas are not adding conditions arbitrarily after I mentioned that the plane 'could' possibly fly if the conditions of the conveyor belt were changed...?

My argument was based (among other principles) on Newton's 3rd Law (equal and opposite reactions on free-running systems)
Take for example:
Your are in a small boat coming into dock (after fishing or something) as you approach the dock you jump from inside the canoe to try to land on the dock but you miss and fall in the water because in jumping you propelled the boat in the opposite direction to where you were heading. This is an application of Newton's third law of motion and is similar to the free-running wheels and conveyor belt originally proposed in this 'puzzle'.

But now!...a motor for the conveyor belt...? http://forums.ubi.com/images/smilies/shady.gif...already running...? http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

I'm not gonna go with you fellas any further on this unless you pay.
____________________________________________
'...How much do you charge Mr lawyer...'I charge $300 to answer three questions...That's a bit steep isn't it...Yes it is, now what is your final question?
______________________________________________
It was one of those cheap flights...instead of inflight movies the pilot flew low over the drive in.
______________________________________________

DaimonSyrius
02-21-2006, 02:25 AM
Originally posted by KrashanTopolova:
My argument was based (among other principles) on Newton's 3rd Law (equal and opposite reactions on free-running systems)
Take for example:
Your are in a small boat coming into dock (after fishing or something) as you approach the dock you jump from inside the canoe to try to land on the dock but you miss and fall in the water because in jumping you propelled the boat in the opposite direction to where you were heading. This is an application of Newton's third law of motion and is similar to the free-running wheels and conveyor belt originally proposed in this 'puzzle'.


As you have amply shown in this (and the previous) thread, you are in dire need of putting more thought into what Newtons's laws mean and when/how do they apply. Alternately, you might need to re-think what 'free-running' means.

So, according to your (not Newton's) 3rd law of motion of aircraft wheels, how would your free-running wheels apply any propulsion to the conveyor belt in any way similar to 'jumping from the boat'? Or, what does 'free-running' mean in your reality?

As was pointed out in the previous thread, you seem to believe that aircraft in their takeoff run behave just like a weird kind of automobile with funny flat things sprouting from its sides, and that the engine is driving the wheels so that the wheels are what is `pushing` the aircraft forward.

Here's news for you http://forums.ubi.com/images/smilies/10.gif they don't.
The landing gear wheels are not propelling anything. They're free-running.

Now that you mentioned fishing or something, there lies the key to what you're doing here, most probably http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

http://www.infonegocio.com/daimon/img/fish-4.jpg

Anyway, thanks once again for the good laughs http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

Cheers,
S.

p-11.cAce
02-21-2006, 05:16 AM
THANK YOU DAIMON! Wheels, skies, floats - whatever you use the plane is going to fly away because its fwd propulsion is INDEPENDENT of its wheels. The only rotational force the wheels experience is what is imparted to them by the surface upon which they rest as the aircraft moves due to the thrust of its propeller or jets.

elphifou
02-21-2006, 05:38 AM
Originally posted by KrashanTopolova:
What?...so now the conveyor has a motor? http://forums.ubi.com/images/smilies/blink.gif

I don't remember a motor for the conveyor being mentioned in the initial setup...hell that introduces all sorts of new conditions


http://forums.ubi.com/images/smilies/88.gif

Krashan, the riddle did <span class="ev_code_YELLOW">not</span> have to mention the presence of a motor. It says that the conveyor belt will match the plane's speed in the opposite direction, whatever that speed may be, including zero.
Now how can you make a conveyor belt deliberately keep up without the help of any kind of energy ?? Whether you pedal or use a motor isn't relevant here...

And no, the presence of a motor does not "introduce all sorts of new conditions", it was implied from the start. This was supposed to be a <span class="ev_code_YELLOW">simple</span> riddle, not an overly complex physics problem. The situation is imaginary and kept simple on purpose, no friction, no loss of energy. I'm sorry, but I think you're making it so complicated because you did not understand the purpose of that puzzle in the first place.

It's a simple riddle, with a simple trick at the start, and a simple answer that comes after the simple exposition of simple causes and effects.

That plane takes off and you know it.
Or if you didn't, maybe now you do.

Regards

Jatro13th
02-21-2006, 06:40 AM
Guys, for Heaven's sake stop this! You see that this gentleman cannot understand basic physics ( or he doesn't want to admit that he is wrong, which I find more probable).

I am begging you to stop this! Please! http://forums.ubi.com/images/smilies/touche.gif

Davinci..
02-21-2006, 07:20 AM
Originally posted by DaimonSyrius:

Now that you mentioned fishing or something, there lies the key to what you're doing here, most probably http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Cheers,
S.

yeha, it took me a while to get the hook out of my mouth.

arjisme
02-21-2006, 08:47 AM
Originally posted by KrashanTopolova:
What?...so now the conveyor has a motor? http://forums.ubi.com/images/smilies/blink.gif

I don't remember a motor for the conveyor being mentioned in the initial setup... Yep, it has a motor that is driving the conveyor at whatever speed the airplane is moving -- exactly matching the airplane's current speed.

Inferring that it has a motor was obvious to most of us as we understand that free running aircraft wheels could never move the conveyor significantly (and if you assume frictionless wheel bearings, would not move it at all).

Popey109
02-21-2006, 09:33 AM
Motor or no...the aircraft is static ralitive to it's saroundings. Unless you think propwash will generate enough lift...this is why we have...runways! http://forums.ubi.com/images/smilies/touche.gif

p-11.cAce
02-21-2006, 09:59 AM
Painfully remving hook from mouth http://forums.ubi.com/images/smilies/16x16_smiley-mad.gif For all of you that think the airplane will not fly I recommend looking into the following organizations of like minded individuals: The Flat Earth Society, The Institue of Yeti Research, and those people who think fossils were put here by the devil to trick us into believeing in evolution....oh and tell Santa Claus, the easter bunny, and the tooth fairy I said hi. http://forums.ubi.com/images/smilies/53.gif Out.

arjisme
02-21-2006, 12:06 PM
Originally posted by Popey109:
Motor or no...the aircraft is static ralitive to it's saroundings. Bzzt, wrong. Please reread the original thread for explanations. There are plenty of very good ones there.

I'm retiring from this debate too. Interesting to find that Krashan thought the conveyor was free-spinning. That explains a lot on where his head was at. Maybe he wasn't fishing. But, this has been covered thoroughly, particularly in the original thread.

Hook <ouch!> removed from mouth! http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

rnzoli
02-22-2006, 06:21 AM
Originally posted by ar****e:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Popey109:
Motor or no...the aircraft is static ralitive to it's saroundings. Bzzt, wrong. Please reread the original thread for explanations. There are plenty of very good ones there.

I'm retiring from this debate too. Interesting to find that Krashan thought the conveyor was free-spinning. That explains a lot on where his head was at. Maybe he wasn't fishing. But, this has been covered thoroughly, particularly in the original thread.

Hook <ouch!> removed from mouth! http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif </div></BLOCKQUOTE>
This happens when people jump into conlusions, and when contradicted, they elaborate their arguments instead of stepping back and looking at the big picture again. How is this proverb? Not seeing the forest from the trees, or something?

Another big problem is that people not reading carefully quickly associate the original riddle with that crazy idea of shortening the runways with a conveyor belt. Only few of them notice, that we say that the plane will fly, after a long take-off run, taking the same or a little more take-off distance as the normal tarmac (so no saving in that respect at all).

So beware of people undertaking a huge effort through arguing with zillons of details, but not taking that 5 minutes to carefully read the riddle first, and if needed, clarifying the underlying assumptions as well... http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Stafroty
02-22-2006, 08:45 AM
only right answer you can give is wrong.

Treetop64
02-22-2006, 01:22 PM
Here fishfishfishfishfish...
Hey fishy-fishy.

fish fish fish...!

Krashan, no one can possibly be that stubbornly ignorant and hard-headed at the same time. Not even Bush.

...well, maybe... http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

KrashanTopolova
02-22-2006, 04:20 PM
I'm glad that at least one of the last few (re)respondents concedes that I'm working with physics.

BTW...if a 'puzzle' has a 'trick' then it is not defining a real physics problem...there are no 'tricks' in physics' only tricky perceptions.

There is not much difference between a conveyor being driven by the impulse of wheels (Newton's 3rd) (where forward momentum and lift is not developed)... and a conveyor belt being driven externally by a third party engine to keep up with the wheels (Newton's 3rd)...where the wheels are still kept in equilibrium with a conveyor belt that does not nothing to impel the aircraft forward unless it generates minute momentum forward at the margins which when magnified by any increasing rotation become significant...however you still, as always, have to prove that any acceleration developed does not reach a terminal velocity from any number of frictional forces or forces of equilibrium arising from Newton's laws...

DaimonSyrius
02-22-2006, 04:44 PM
Quote: "There is not much difference between a conveyor being driven by the impulse of wheels (Newton's 3rd).../..."

http://forums.ubi.com/images/smilies/10.gif the wheels are providing no impulse to anything, not even to a loose conveyor belt, they're free-running wheels, this is an aircraft and <span class="ev_code_YELLOW">not a car</span>

Quote: "and a conveyor belt being driven externally by a third party engine to keep up with the wheels (Newton's 3rd)...where the wheels are still kept in equilibrium with a conveyor belt that does not nothing to impel the aircraft forward unless"

http://forums.ubi.com/images/smilies/10.gif the propeller is doing everything to impel forwards (= propel) the aircraft (remember this is about <span class="ev_code_YELLOW">an aircraft?</span>)

Quote: ".../...it generates minute momentum forward at the margins which when magnified by any increasing rotation become significant...however you still, as always, have to prove that any acceleration developed does not reach a terminal velocity from any number of frictional forces or forces of equilibrium arising from Newton's laws..."

http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/partyhat.gif http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/partyhat.gif http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/partyhat.gif http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/partyhat.gif http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/partyhat.gif http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/partyhat.gif http://forums.ubi.com/images/smilies/88.gif

Farewell, and cheers, KrashanTopolova, good luck at your physics job http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

S.

elphifou
02-22-2006, 05:25 PM
Originally posted by KrashanTopolova:
I'm glad that at least one of the last few (re)respondents concedes that I'm working with physics.

BTW...if a 'puzzle' has a 'trick' then it is not defining a real physics problem...there are no 'tricks' in physics' only tricky perceptions.

There is not much difference between a conveyor being driven by the impulse of wheels (Newton's 3rd) (where forward momentum and lift is not developed)... <span class="ev_code_YELLOW">and a conveyor belt being driven externally by a third party engine to keep up with the wheels</span> (Newton's 3rd)...where the wheels are still kept in equilibrium with a conveyor belt that does not nothing to impel the aircraft forward unless it generates minute momentum forward at the margins which when magnified by any increasing rotation become significant...however you still, as always, have to prove that any acceleration developed does not reach a terminal velocity <span class="ev_code_YELLOW">from any number of frictional forces</span> or forces of equilibrium arising from Newton's laws...

http://forums.ubi.com/images/smilies/35.gif http://forums.ubi.com/images/smilies/88.gif

1) The conveyor belt is supposed to keep up with the PLANE, not the wheels !
2) no friction; this is imaginary
How many times do we have to repeat this ?

http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif Oh, God, if it wasn't so hilarious, I'd have given up long ago...

KrashanTopolova
02-22-2006, 10:27 PM
Let me get this straight!...are you saying that the wheels are not keeping up with the plane to which they are attached...? http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

if not (I don't know why not)or despite that...I might be able to apply maths to work out if your astounding conveyor system works.

That is if anyone can supply from historical sources the following flight characterisitics for the A6M2 and the P-39M Airacobra:

A6M2:
1. takoff speed ( at time of rotation, no pilot input)
2. speed at rotation of tailwheel (no pilot input)

P-39M (Allison V1710 engine):
1. takeoff speed (speed at rotation, no pilot input)

If no historical sources then please resort to the FM (I can't at the moment). It's good enough for the purpose.

Z4K
02-22-2006, 11:09 PM
Um, Krashan, as it seems you didn't actually read it the first time, here it is again:


Originally posted by georgeo76:

You construct a conveyor belt(treadmill) on a runway. A normal airplane (jet or prop) sits at the end of the strip, ready to roll out. The conveyor is fixed so that how ever fast the airplane travels, the conveyor moves at an equal and opposite direction.

Can the aircraft take off?


The system the riddle describes includes:
* One aircraft;
* One conveyor belt, with the aircraft on it;
* One undefined (and possibly magical) system which measures the speed of the plane, and drives the conveyor belt at that same speed, but in the opposite direction.

It's not a physics problem. It is more of a reading comprehension and logical thinking test. Which you spectacularly failed.


The "aircraft doesn't have to keep up with the wheels" business is saying that while the aircraft is moving with velocity x (hell, since you wanted to use calculus make it dx, it makes no difference), the wheels are rotating <span class="ev_code_YELLOW">at the rate they would on a plane moving with velocity 2x (or 2dx, if you were doing it that way) on stationary ground</span>. The conveyor, of course, is moving with velocity -x (or -dx).

Even if it were a physics problem (it still isn't), your explanations about "the kinetic energy stored in the wheels" et al clearly show you have a lot of work to do to develop your physics understanding.



edit: if you're trolling, your pseudo-physics babble is perfect. I couldn't begin to come up with fallacious concepts like yours. Discrete "thrusts" of a propellor indeed - inspired!

Stafroty
02-22-2006, 11:44 PM
maybe there isnt just enought information to solve the question.

p-11.cAce
02-23-2006, 05:49 AM
The only "trick" to this is the artful fishing that is taking place. Actually this is pretty fun and a good brain-teaser for those who cannot get it into their heads that airplanes are not cars! I think if the original riddle had stated that the airplane was using skies intead of wheels more of the "it will not fly" crowd would have understood their error.

MajorBloodnok
02-23-2006, 06:06 AM
I can't believe I just wasted 12 minutes reading this thread. http://forums.ubi.com/images/smilies/35.gif

Treetop64
02-23-2006, 09:45 AM
Originally posted by Stafroty:
maybe there isnt just enought information to solve the question.

No, Stafroty.

It's a simple riddle with a simple answer that ended up becoming a Pandora's Box, no thanks to a very small minority that decided that they were going to show everyone else how "smart" they were.

If you think there isn't enough info for an answer, or as you say "...there is no right answer.", then you're just not getting it. And that's fine.

Krashan, on the other hand, seems absolutely hell bent on showing everyone else - who have all since gotten the riddle long ago - that they are all wrong, and that he is right. Thank him for making this a much more convoluted process than it was ever intended to be.

Besides, Krashan got so distracted by details and physics, (well, his understanding of physics anyway), that he missed unspoken, but completely obvious implications of the riddle; that the belt would need some sort of power to independently match the aircraft's speed in the opposite direction. He completely missed the point of the riddle, and in his persistent arguing, removed all enjoyment out of it...

He even continued this campaign by starting a new thread even after the mods locked the previous one, and his condescending tone is reflected by what he chose to type as a title, and in the first sentences of his post.

The funny thing is that if one didn't know any better, his technobabble actually sounds legitimate! However, correct technical understading or no, the riddle is not that complicated. It is a simple, critical thinking brain teaser. Somehow, Krashan's "system" simply refuses to absorb that.

Either that, or he's one hell of a good fisherman! http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

TgD Thunderbolt56
02-23-2006, 12:16 PM
IBTL

rnzoli
02-23-2006, 01:57 PM
Originally posted by Treetop64:
Either that, or he's one hell of a good fisherman! http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif
Or a person unable to admit defeat. His behaviour reminds me of a time, when I had to sort out among a group of engineers who is doing his job well, and who isn't. Now the problem was that they all knew the subject far better than me, so they could easily bull**** me. However, I found a simple way to know, whether they did a good work with something or not. I asked them to simplify their analysis and summarize. When I understood it the simple way, I started to make simple cross-questions. If the guy was able to intercept my thoughs, point out the problem in a simple way and convince me that he was right - he was indeed right. But if he started to retreat behind his technical mambo-jumbo, and focused on disrupting my logic instead of intercepting it and re-directing it back to what he was saying before - he was surely wrong. I have told them many times: if you cannot summarize your thoughts in a few sentences, you are not understanding the main point of your own analysis, and you haven't done a good work.

Krashan reminds me of the latter. Several people tried to convince him in many different ways, and all he did was to 'escape' behind complex explanations. He was always on defensive, he couldn't point out in a simple way, where we are wrong. Even people thinking that he is right can't follow his argumentation. We don't have to convince him, he may believe whatever he wants in his own mind, he couldn't convince anyone about it. He lost the argument in the orginal thread, he lost the argument in this one too. He is a sour loser, unable to digest his defeat. That's why there's no point in fighting with him. Let him believe whatever garbage he wants, he is awfully alone.

KrashanTopolova
02-23-2006, 07:29 PM
I'm not all bad...I do include clues as I write...

Imagine this:

a conveyor belt in motion...an object with no wheels on it...result, the object goes in direction of conveyor belt motion...it therefore has speed (a scalar quantity) and direction therefore it has velocity, which is a vector quantity...(the velocity is constant in this case).

Now envisage a 1500kg (say) object with wheels (tri-cycle undercarriage like on a PQ-39 on a chassis) placed on the moving conveyor. It also travels in the direction of the conveyor belt surface because it too, like the object with no wheels, has no force acting in the opposite direction to the conveyor belt to oppose being taken along by the conveyor belt.

But it doesn't move in the direction of the conveyor belt as easily as the object with no wheels. This is Newton's 3rd law in action.
It means that the Resultant force of the conveyor belt is overwhelmingly backwards from the direction the object with wheels is designed to go

Now consider that the object with wheels has force independant of the conveyor belt force and which independant F acts in the opposite direction of the conveyor belt surface.
At some point the two opposing forces will be in equilibrium (at this equilibrium point you could imagine that you, being like Superman, are holding the object with wheels stationary to the air and on the belt; just letting the conveyor belt spin the object's wheels. This is an equilibrium state in which the object has no forward momentum relative to the air around it because it has the sum of all forces acting on it = 0

You believers are assuming that because the conveyor acts on the bottom of the aircraft's wheels and the thrust acts through the top of the aircraft wheels that although spinning much faster than normal (at that point in time at least) the aircraft will move forward on the conveyor belt.

But this is only possible if the Thrust force is greater than the conveyor + drag forces acting in the opposite direction. You assume this is so but state in contradiction that the conveyor must keep up with the wheels (as a condition)
However, their speed (scalar) is determined by the thrust while the speed of the conveyor is determined by the speed of the wheels (as a condition).

this means there can be little or no velocity because there is no direction vector to accompany that speed of the wheels because that direction is prevented from coming into existence by the requirement that the conveyor speed must match that of the wheels...

Therefore if it has any velocity then a=0 at that point of equilibrium => no lift.
You must show that the aircraft does not go into this equilibrium state before you can claim that the aircraft can fly from the conveyor

The problem as set out is one of '...which came first the chicken or the egg...'

BaldieJr
02-23-2006, 07:47 PM
wait. where is the runway located?

Akronnick
02-23-2006, 07:47 PM
Originally posted by KrashanTopolova:
I'm not all bad...I do include clues as I write...

Imagine this:

a conveyor belt in motion...an object with no wheels on it...result, the object goes in direction of conveyor belt motion...it therefore has speed (a scalar quantity) and direction therefore it has velocity, which is a vector quantity...(the velocity is constant in this case).

Now envisage a 1500kg (say) object with wheels (tri-cycle undercarriage like on a PQ-39 on a chassis) placed on the moving conveyor. It also travels in the direction of the conveyor belt surface because it too, like the object with no wheels, has no force acting in the opposite direction to the conveyor belt to oppose being taken along by the conveyor belt.

But it doesn't move in the direction of the conveyor belt as easily as the object with no wheels. This is Newton's 3rd law in action.
It means that the Resultant force of the conveyor belt is overwhelmingly backwards from the direction the object with wheels is designed to go

Now consider that the object with wheels has force independant of the conveyor belt force and which independant F acts in the opposite direction of the conveyor belt surface.
At some point the two opposing forces will be in equilibrium (at this equilibrium point you could imagine that you, being like Superman, are holding the object with wheels stationary to the air and on the belt; just letting the conveyor belt spin the object's wheels. This is an equilibrium state in which the object has no forward momentum relative to the air around it because it has the sum of all forces acting on it = 0

You believers are assuming that because the conveyor acts on the bottom of the aircraft's wheels and the thrust acts through the top of the aircraft wheels that although spinning much faster than normal (at that point in time at least) the aircraft will move forward on the conveyor belt.

But this is only possible if the Thrust force is greater than the conveyor + drag forces acting in the opposite direction. You assume this is so but state in contradiction that the conveyor must keep up with the wheels (as a condition)
However, their speed (scalar) is determined by the thrust while the speed of the conveyor is determined by the speed of the wheels (as a condition).

this means there can be little or no velocity because there is no direction vector to accompany that speed of the wheels because that direction is prevented from coming into existence by the requirement that the conveyor speed must match that of the wheels...

Therefore if it has any velocity then a=0 at that point of equilibrium => no lift.
You must show that the aircraft does not go into this equilibrium state before you can claim that the aircraft can fly from the conveyor

The problem as set out is one of '...which came first the chicken or the egg...'

raaaid, is that you? SirRobin1337? RBJ?

conveyor is new best, be sure!

elphifou
02-23-2006, 08:01 PM
Either this guy's downright crazy or he's been taking the **** out of us.

I wonder... he said "beware" http://forums.ubi.com/images/smilies/blink.gif

Cajun76
02-23-2006, 08:08 PM
Originally posted by rnzoli:
Or a person unable to admit defeat. His behaviour reminds me of a time, when I had to sort out among a group of engineers who is doing his job well, and who isn't. Now the problem was that they all knew the subject far better than me, so they could easily bull**** me. However, I found a simple way to know, whether they did a good work with something or not. I asked them to simplify their analysis and summarize. When I understood it the simple way, I started to make simple cross-questions. If the guy was able to intercept my thoughs, point out the problem in a simple way and convince me that he was right - he was indeed right. But if he started to retreat behind his technical mambo-jumbo, and focused on disrupting my logic instead of intercepting it and re-directing it back to what he was saying before - he was surely wrong. I have told them many times: if you cannot summarize your thoughts in a few sentences, you are not understanding the main point of your own analysis, and you haven't done a good work.

Krashan reminds me of the latter. Several people tried to convince him in many different ways, and all he did was to 'escape' behind complex explanations. He was always on defensive, he couldn't point out in a simple way, where we are wrong. Even people thinking that he is right can't follow his argumentation. We don't have to convince him, he may believe whatever he wants in his own mind, he couldn't convince anyone about it. He lost the argument in the orginal thread, he lost the argument in this one too. He is a sour loser, unable to digest his defeat. That's why there's no point in fighting with him. Let him believe whatever garbage he wants, he is awfully alone.

http://forums.ubi.com/images/smilies/10.gif You just descibed a certain 109 fanatic... http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif He used to part of a Hungarian Polka/Punk duo called "Ubertwins" http://forums.ubi.com/images/smilies/metal.gif http://forums.ubi.com/images/smilies/inlove.gif But now I hear he's doing a one fan show out in Vegas, with tiggers.

http://img.photobucket.com/albums/v30/Cajun76/Royandtiger.gif

http://forums.ubi.com/images/smilies/halo.gif

(Borrowed without permission from Tagert, ty)

Burnzoire1
02-23-2006, 08:21 PM
Ok to begin with, both conveyor and aircraft are stationary. Yes?

Then, the aircraft goes full throttle at say 3000rpm (whatever). NOTHING will stop the aircraft moving in the first moments with that kind of force (i.e greater than the simple friction the conveyor creates by spinning the wheels under the aircraft's weight)... It'll start to move forward and the conveyor will match it's speed (which to begin with isn't going to be much, certainly not enough to stop the power of the engine). The aircraft builds up speed and it becomes really obvious that the conveyor moving at 100knots or so isn't going to do diddly squat. The engine, assuming it's appropriate for the aircraft's weight, is not going to be outpowered by some force spinning it's wheels! This force is not directed at the aircraft, it's directed at the wheels which spin independantly of the aircraft. The only backwards force you will get is a very slight fraction of the conyeyor speed that is created by the friction in the wheels/skis/banana peels. Are you really saying that this friction will provide more 'thrust' than the aircraft's powerplant??????????????????????

It's pointless though, you won't answer my points but instead start anotehr WILD tangent about newton's laws.

Davinci..
02-23-2006, 08:40 PM
Originally posted by Burnzoire:
Are you really saying that this friction will provide more 'thrust' than the aircraft's powerplant??????????????????????


he's not saying anything... he's just pretending to, to save face.

why admit you are wrong, when you can toss words around that you dont understand, and hope everyone else dosnt understand them either, so that you can seem like you know what you are talking about.

this is basically whats been going on here(that or some fishing).

where are the mods http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

Stafroty
02-23-2006, 10:34 PM
Originally posted by Treetop64:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Stafroty:
maybe there isnt just enought information to solve the question.

No, Stafroty.

It's a simple riddle with a simple answer that ended up becoming a Pandora's Box, no thanks to a very small minority that decided that they were going to show everyone else how "smart" they were.

If you think there isn't enough info for an answer, or as you say "...there is no right answer.", then you're just not getting it. And that's fine.

Krashan, on the other hand, seems absolutely hell bent on showing everyone else - who have all since gotten the riddle long ago - that they are all wrong, and that he is right. Thank him for making this a much more convoluted process than it was ever intended to be.

Besides, Krashan got so distracted by details and physics, (well, his understanding of physics anyway), that he missed unspoken, but completely obvious implications of the riddle; that the belt would need some sort of power to independently match the aircraft's speed in the opposite direction. He completely missed the point of the riddle, and in his persistent arguing, removed all enjoyment out of it...

He even continued this campaign by starting a new thread even after the mods locked the previous one, and his condescending tone is reflected by what he chose to type as a title, and in the first sentences of his post.

The funny thing is that if one didn't know any better, his technobabble actually sounds legitimate! However, correct technical understading or no, the riddle is not that complicated. It is a simple, critical thinking brain teaser. Somehow, Krashan's "system" simply refuses to absorb that.

Either that, or he's one hell of a good fisherman! http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif </div></BLOCKQUOTE>


have you ever spent an little though for that, Maybe, just maybe if you are anyway wrong??

All how you get the answer is assuming more information in the question than there really is. on that, you and many others get distracted, as well about the idea, that its yes/no question, and you think its only way to answer it. You can bring your point up time after time, explaining the same assumptions how speeds and where speed is measured for the plane etc. it really is pandoras box, for you and the opposition you have here.

rnzoli
02-24-2006, 02:32 AM
Originally posted by KrashanTopolova:
I'm not all bad...I do include clues as I write...
You aren't bad at all, I personally like you. It is always good when someone plays the devil's advocate. It's just that when we go around in circles, it becomes boring like hell for me, while other get irritated.


Originally posted by KrashanTopolova:
while the speed of the conveyor is determined by the speed of the wheels (as a condition).

This is where you are assuming something different from the original riddle.. No. The conveyor speed is determined by the airspeed of the plane vs. the airmass, not the speed of the wheels.

Big difference, because it has been said many times, that the wheels will spin 2x faster than normal during takeoff from the reverse-moving belt.

Z4K
02-24-2006, 05:28 AM
Originally posted by Stafroty:

have you ever spent an little though for that, Maybe, just maybe if you are anyway wrong??



Actually, yes. I got fooled by the question the first time I read it. Like many others I jumped to the conclusion that the question described a system where the plane was immobile - leading to the obvious "no it won't take off" answer.

When I actually stopped to read and digest the system in the problem (thanks to prompting from Akronnick) the truth was plain to see (ie. the conveyor doesn't affect the plane's motion).
____________________________

Re: all the "KrashanTopolova's fishing" comments, I don't think he is (http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/5961027314/r/6511096514#6511096514). At least, I think his grasp of physics genunely is as bad as it appears.

The trouble is, he ignores every single post that raises points he can't answer. Or that interfere with the answer he's too emotionally invested in to really critique.

KrashanTopolova
02-26-2006, 04:04 PM
Still you fellas have not picked up on the clues...

If the mass with wheels goes backward on the conveyor belt (after an initial momentum forward due to Newton's 3rd) then it is on an acceleration vector NOT a constant velocity vector like the mass with no wheels placed on the conveyor belt...moreover it is accelerating in the direction of the conveyor belt momentum.

Ground friction is an important ******ant to momentum of the aircraft but not the only factor as it generally decreases with any momentum (molecules gain less surface area grip). But still that adds no argument for the conveyor belt flyers.

Because it is an acceleration vector in the reverse direction to that the aircraft wants to go it means that the mass with wheels is heading towards equilibrium while it is on the conveyor belt when normal aircraft thrust is introduced...Simple!...now add wings and see if they work...!

Not quite like trying to take off on ice but close!

This equilibrium condition is assured by the 'puzzle' condition that the conveyor belt must keep up with the wheels...

The wheels cannot be left out of the equation because there is no other medium to relate the conveyor belt forces to the fixed points in space in which both aircraft and conveyor belt exist...

The aircraft will sit on the conveyor belt at either zero or a constant velocity below rotation speed, wheels spinning madly, while the conveyor belt flyers shout 'Go...Go...Go...you bastard...', and the pilot has either a stall warning ringing in his ears or has lunch in the cockpit!
_______________________________________________
'...A Jury is the one thing that never works properly once it's been fixed...'
_______________________________________________

KrashanTopolova
02-26-2006, 04:23 PM
________________________________________________
This is where you are assuming something different from the original riddle.. No. The conveyor speed is determined by the airspeed of the plane vs. the airmass, not the speed of the wheels.

Big difference, because it has been said many times, that the wheels will spin 2x faster than normal during takeoff from the reverse-moving belt
_______________________________________________
Sorry...there is no airspeed there is only groundspeed on the conveyor belt...

If the aircraft takes off (by, say, pixies pulling it into the air) then it will have airspeed...every speed below that is groundspeed below the design speed of rotation into liftoff.

The original conditions stated that the conveyor belt keeps up with the speed of the wheels...!

thus there is no speed relative to the airmass in which the aircraft exists...because there is no vector associated with the wheel speed to allow Velocity of the aircraft to come into existence within the associated airmass...

elphifou
02-26-2006, 04:26 PM
Originally posted by KrashanTopolova:
The original conditions stated that the conveyor belt keeps up with the speed of the wheels...!

http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

I assure you Krashan is taking the **** out of us.

Jatro13th
02-26-2006, 05:10 PM
Jesus H. Christ STOP THIS!!!!! I will believe it in the end. Its the first time I see so much conviction to prove that black is white or vice versa!

One thing's for sure, Krashan replys are getting too complicated for me to understand (or even for him to understand).

For me this is simple, if the airplane cant take off, then we shouldn't be able to push the carts in the supermarkets, and our lives would be much happier and healthier, but thats not teh case.

Try this one for a change. Go to an airport or wherever else there might be any conveyor belts and take a cart for the luggage. Now go to the belt and place the cart on it. place yourself outside the belt and start pushing the cart in the opposite way the belt goes. You will see that not only will you be able to match the belts speed (which will have as a result the belt to run under the cart with twice the speed the static ground has) but you will be able to reach greater speeds.

Youcan even tell the technicians to make it run faster, and still you will be able to outrun it.

Now, in our case, the cart is the plane, the belt is teh belt, the cart's wheels are the plane's wheels and your hand is teh propeller gusing through teh air.

Now if you do tihs experiment and dont succeed, I would suggest to go to teh gym!!!!!!!!!!!!

End of teh discussion!

Jatro13th
02-26-2006, 06:00 PM
Krashan's arguments sound like this:

A wedding ring is a ring. A hoola hoop is a ring. Therefore, a wedding ring is a hoola hoop!

His way of forming incomprehensible sentences and getting away with it is the following:

The Evangelists were four, three of which were the following two: Lucas!

Now we form them into one Rossinian Finale:

The airmass is not moving through the feathers of the everturning propeller of two pixies turning the wheels of the conveyor belt, therefore, the first and fifth laws of Newton coincide with the evolving theory of relativity, which states that the momentum of the pilots feet will differ with those of the ground, and it is imperative that the plane stayed static in order to place the velocity vector in accordance with the acceleration vector and absolute measure. This proves that a dog will fly when a sparrow falls to the earth!

OF course!, why didnt I think of it before?

The answer was right in front of my eyes all this time!

Thanks Krashen for opening them letting me see teh Light!!!

p-11.cAce
02-26-2006, 06:14 PM
http://forums.ubi.com/images/smilies/11.gif BRAVO!

Jatro13th
02-26-2006, 06:18 PM
Thanks mate, and thanks to Krashan for the laughs! http://forums.ubi.com/images/smilies/11.gif We want more!!!! We should make a sticky out of this thread!

KrashanTopolova
02-27-2006, 03:58 PM
Please let any panic be orderly...


Now:
perhaps it may be easier for you blokes to look at the problem from the perspective of energy and it's conservation...


Now:
Say the aircraft engine develops full thrust at 2 000hp (1 491kW)...for example the F6F.

Now you might say that not all that work (in kW) is translated to the wheels by the propellor because the propellor is not directly connected to the wheels.

But whatever work in kW is delivered by the thrust to the wheels to make them turn is matched proportionally by the conveyor (the stated condition). This however ensures equilibrium.

Now go back to one my earlier posts which stated that a mass with wheels on a free-running conveyor will first move in the direction opposite the direction of the conveyor (from Newton's 1st concerning inertia) then be carried in the direction of the conveyor belt regardless of the wheels turning in the opposite direction. This is because of Newton's 3rd (equal and opposite reaction) and there is no force vector to counter that direction of momentum in that hypothetical example. Thus the mass with wheels has a constant velocity on the conveyor belt in the direction reverse to where it points.

Now because in the 'puzzle' the conveyor is stated to provide Work to automatically match the speed of the wheels, it is that condition that would change the above constant velocity vector into an acceleration vector.
Then there are two competing acceleration vectors on the powered conveyor: thrust and energy momentum.

It is of course possible for a human bean to supply more than enough thrust to move a lightweight trolley forward against an airport conveyor belt but a similar task is not possible with a real aircraft for its power to weight ratio is designed for a non-moving takeoff surface.

Now if youse go back to one of my earlier posts in the original thread ('an interesting puzzle') you will notice that I conceded the possibility that if the initial inertia momentum of the aircraft on the conveyor is caught and built on by the thrust then it might be sufficient on a FREE-RUNNING conveyor for the aircraft to develop enough thrust to proceed along the conveyor belt but that it is more likely that the inertia and drag on a reverse-running conveyor will cause the aircraft to go into equilibrium on the conveyor at either zero velocity or a terminal velocity.

Now however, with the conveyor putting WORK into the system the acceleration vector mentioned above is assured of arising to make the aircraft go into equilibrium where all Net forces acting on the aircraft are zero or even negative.

Ergo: the aircraft does not move forward relative to a fixed point in space outside the conveyor belt.

Therefore either of the following states exist: no velocity or acceleration = zero (terminal velocity).

Therefore: no lift.

You have not made the 'puzzle' idiot-proof!

______________________________________________
Signs on the wall at my Flight Training Centre:

'...Make it idiot-proof and someone will make a better idiot...'

'...All inanimate objects can move just enough to get in your way...'

'...An error in the premise will appear in the conclusion...'
_______________________________________________

BillPosters
02-27-2006, 04:35 PM
You're smoking crack. The puzzle as it is stated in the original thread states that the conveyor belt matches the speed of the *plane*, not the wheels. This means that the plane can and will move forward and will take off if we assume the effects of friction (wheels against conveyor, wheel bearings etc) to be negligible.

If the conveyor was matching the speed of the *wheels* then, yes, the plane would be stationary and produce no lift (I think?). This is not how the puzzle was originally stated however and the incessant flogging of this poor dead horse needs to end.

Treetop64
02-27-2006, 05:49 PM
Originally posted by KrashanTopolova:

Blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah Blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah...

...to infinity and back.


Bro, no hostile intent, but give it a rest already. You're not doing yourself any favors...

Jatro13th
02-27-2006, 06:26 PM
But whatever work in kW is delivered by the thrust to the wheels to make them turn is matched proportionally by the conveyor (the stated condition). This however ensures equilibrium.


http://forums.ubi.com/images/smilies/16x16_smiley-sad.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif http://forums.ubi.com/images/smilies/35.gif http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif http://forums.ubi.com/images/smilies/compsmash.gif http://forums.ubi.com/images/smilies/88.gif

This confirms my two last posts!

Who on earth said such a thing? If it was stated by someone, this is wrong. You mean that the belt's energy transmitted to the wheels giving them circular movement is about the same as with the propeller's?

Boy, that means that the belt is moving at supersonic speeds!
So, the energy given by the belt to the wheels BY FRICTION, is the same as with the energy given by the engine to the wheels via a king-pin?
That is impossible, unless the brakes are full on. That is equilibrium, and ze plane stays static mein herr. If the brakes are released, then the plane is free as a bird.

The whole thing is like you are trying to prove that we can walk freely on ice like we do on concrete!

C'moooooooon, admit it! You are fishing!

Let's keep up the good work!

" We are now... no longer the Knights Who Say 'Ni'. Shh! We are now the Knights Who Say 'Ecky- ecky- ecky- ecky- pikang- zoop- boing- goodem- zoo- owli- zhiv'."

Burnzoire1
02-27-2006, 06:34 PM
Originally posted by KrashanTopolova:
Now because in the 'puzzle' the conveyor is stated to provide Work to automatically match the speed of the wheels ...
_______________________________________________

http://www.777project.com/images/photos_diagrams/MAIN_-_Standby_AirSpeed_Indicator.jpg
http://www.allstar.fiu.edu/aero/images/imac.gif
http://xflight.powerweb.de/original/parts/center_console/airspeed/0004_117.jpg
http://www.precision-aircraft.net/Sales%20Items/ASI.jpg

Which one of these measures the speed of an aircraft's wheels?

elphifou
02-27-2006, 09:02 PM
Originally posted by BillPosters:
You're smoking crack. The puzzle as it is stated in the original thread states that the conveyor belt matches the speed of the *plane*, not the wheels. This means that the plane can and will move forward and will take off if we assume the effects of friction (wheels against conveyor, wheel bearings etc) to be negligible.

If the conveyor was matching the speed of the *wheels* then, yes, the plane would be stationary and produce no lift (I think?). This is not how the puzzle was originally stated however and the incessant flogging of this poor dead horse needs to end.

Unfortunately, you're wasting your time http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

I told him twice, maybe 3 times, that the conveyor belt is supposed to match the plane's speed...

And that was, not counting what the others told him, <span class="ev_code_YELLOW">before</span> his latest post in which you can find, guess what :


Now because in the 'puzzle' the conveyor is stated to provide Work to automatically <span class="ev_code_YELLOW">match the speed of the wheels</span>, it is that condition that would change the above constant velocity vector into an acceleration vector.

it's like pi$$ing in the wind, if you ask me...

KrashanTopolova
02-27-2006, 09:04 PM
Originally posted by BillPosters:
You're smoking crack. The puzzle as it is stated in the original thread states that the conveyor belt matches the speed of the *plane*, not the wheels. This means that the plane can and will move forward and will take off if we assume the effects of friction (wheels against conveyor, wheel bearings etc) to be negligible.

If the conveyor was matching the speed of the *wheels* then, yes, the plane would be stationary and produce no lift (I think?). This is not how the puzzle was originally stated however and the incessant flogging of this poor dead horse needs to end.
_______________________________________________
What?...so now the wheels are not attached to the plane...?

(chicken before the egg)

What?...so now the speed of the plane is different to any 'speed' of the landing struts through the airmass?...

What?...so now the axles which are attached to the landing struts are isolated from any 'speed' of the aircraft?...

Wha?...so now the wheels are not attached to the axles which are attached to the landing struts which are attached to the aircraft which is attached to a (hypothetical)groundspeed...?...

WHA?...so now the aircraft fuselage is in some dimension other than the 3-dimensional space in which conveyor, air mass, struts linked to axles linked to wheels exists?...

without the wheels there is no possibility of 'moving forward' relative to a fixed point in space.

You should isolate rotational direction from linear direction otherwise one becomes muddled.

No-one has picked up on the 'fact' that if the conveyor belt was slower than the wheel rotation then the aircraft would accelerate into flight on the conveyor belt (eventually).
(Hint: What would happen if the conveyor belt was faster than the rotation of the wheels...?)
_______________________________________________
'...If a man says something in the woods and no woman hears him is he still wrong...'?
_______________________________________________

Burnzoire1
02-27-2006, 09:17 PM
Originally posted by KrashanTopolova:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BillPosters:
You're smoking crack. The puzzle as it is stated in the original thread states that the conveyor belt matches the speed of the *plane*, not the wheels. This means that the plane can and will move forward and will take off if we assume the effects of friction (wheels against conveyor, wheel bearings etc) to be negligible.

If the conveyor was matching the speed of the *wheels* then, yes, the plane would be stationary and produce no lift (I think?). This is not how the puzzle was originally stated however and the incessant flogging of this poor dead horse needs to end.
_______________________________________________
What?...so now the wheels are not attached to the plane...?

(chicken before the egg)

What?...so now the speed of the plane is different to any 'speed' of the landing struts through the airmass?...

What?...so now the axles which are attached to the landing struts are isolated from any 'speed' of the aircraft?...

Wha?...so now the wheels are not attached to the axles which are attached to the landing struts which are attached to the aircraft which is attached to a (hypothetical)groundspeed...?...

WHA?...so now the aircraft fuselage is in some dimension other than the 3-dimensional space in which conveyor, air mass, struts linked to axles linked to wheels exists?...

without the wheels there is no possibility of 'moving forward' relative to a fixed point in space.

You should isolate rotational direction from linear direction otherwise one becomes muddled.

No-one has picked up on the 'fact' that if the conveyor belt was slower than the wheel rotation then the aircraft would accelerate into flight on the conveyor belt (eventually).
(Hint: What would happen if the conveyor belt was faster than the rotation of the wheels...?)
_______________________________________________
'...If a man says something in the woods and no woman hears him is he still wrong...'?
_______________________________________________ </div></BLOCKQUOTE>

Wow.

I'm at a loss for words, even a 5 year old would know what you're saying makes no sense what-so-ever.

You still don't understand these simple facts:

1) The puzzle refers to the speed of the aircraft. This assumes:
2) Aircraft speed is measured by AIR speed not ground speed.
3) Aircraft wheels spin independantly of the aircraft and thus their speed (read: rpm) on the conveyor belt is irrelevant.
4) The conveyor belt matches the aircraft's air speed.

If you can prove either of those points to be wrong, eb my guest. If not, shut up already!

KrashanTopolova
02-27-2006, 09:26 PM
Originally posted by Burnzoire:
__

Wow.

I'm at a loss for words, even a 5 year old would know what you're saying makes no sense what-so-ever.

You still don't understand these simple facts:

1) The puzzle refers to the speed of the aircraft. This assumes:
2) Aircraft speed is measured by AIR speed not ground speed.
______________________________________________
There is no airspeed if and until the aircraft gets off the conveyor. Up to that hypothetical point there is only ground speed which takes place on the conveyor belt
______________________________________________
3) Aircraft wheels spin independantly of the aircraft and thus their speed (read: rpm) on the conveyor belt is irrelevant.
______________________________________________
something that is part of the aircraft's system of momentum is not independant either in space or in function and therefore certainly not irrelevant to any forces acting on the aircraft
______________________________________________
4) The conveyor belt matches the aircraft's air speed.
______________________________________________
Again...the conveyor belt never stops matching the aircraft's speed...the point is that there is no aircraft velocity to which the conveyor may match
______________________________________________

If you can prove either of those points to be wrong, eb my guest. If not, shut up already![/QUOTE]
______________________________________________
Now that's being a 5 year old...!
______________________________________________

Burnzoire1
02-27-2006, 09:27 PM
whilst you're at it, take a look at those gauges I posted... note none of them show GROUND speed. It's a pretty safe assumption to use airspeed for the speed of an airplane - you you've chosen ground speed and ignore the fact that everyone else in the universe is talking about air speed. AIR speed man, we're talking abotu an aircraft not a car!

KrashanTopolova
02-27-2006, 09:32 PM
Originally posted by Burnzoire:
whilst you're at it, take a look at those gauges I posted... note none of them show GROUND speed. It's a pretty safe assumption to use airspeed for the speed of an airplane - you you've chosen ground speed and ignore the fact that everyone else in the universe is talking about air speed. AIR speed man, we're talking abotu an aircraft not a car!

______________________________________________
airspeed is measured by pressure differentials thrpough the pitot tube...it depends on measures such as air pressure at sea level and air pressures at altitude.
Airspeed and groundspeed are, for all intents and purposes, the same when an aircraft is travelling on the ground. The istuation changes only when the aircraft becomes airborne
________________________________________________

Davinci..
02-27-2006, 09:44 PM
Originally posted by KrashanTopolova:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Burnzoire:
whilst you're at it, take a look at those gauges I posted... note none of them show GROUND speed. It's a pretty safe assumption to use airspeed for the speed of an airplane - you you've chosen ground speed and ignore the fact that everyone else in the universe is talking about air speed. AIR speed man, we're talking abotu an aircraft not a car!

______________________________________________
airspeed is measured by pressure differentials thrpough the pitot tube...it depends on measures such as air pressure at sea level and air pressures at altitude.
Airspeed and groundspeed are, for all intents and purposes, the same when an aircraft is travelling on the ground. The istuation changes only when the aircraft becomes airborne
________________________________________________ </div></BLOCKQUOTE>

wow, you are like the complete opposite of a pilot...

Burnzoire1
02-27-2006, 09:56 PM
I had to delete my post about spped because well, speed is irrelevant. The conveyor belt can go as fast or slow as it damn well wants to. The conveyor matches the aircraft's speed, not vice verca.

The aircraft will move, there's no denying that. The powerplant will propell it through the air. The conveyor will just spin the wheels - remember how wheels work? Man invented them a long time ago.

so... I can't think of anything that will stop the aircraft from moving, and through all your ranting neither can you.

Davinci..
02-27-2006, 10:06 PM
Originally posted by Burnzoire:
you you've chosen ground speed and ignore the fact that everyone else in the universe is talking about air speed. AIR speed man, we're talking abotu an aircraft not a car!

you must have missed this "gem"

Originally posted by KrashanTopolova:
it takes off because it has the thrust to reach a groundspeed (note: not airspeed)


and also this

Originally posted by KrashanTopolova:
Methinks energy momentum has to be delivered through the wheels in contact with a non-moving surface else there is no momentum and no forward thrust and no lift...

he believes planes move forward because its power is deliverd through its wheels to the ground..

and that it only takes off when it reaches a certain speed over the ground.

this is why he is unable to grasp the concepts involved here(he is simply not educated enough, to understand what is going on). from those 2 comments alone, you can completely write off anything he says or has said(especially pertaining to this riddle).

Burnzoire1
02-27-2006, 10:42 PM
For all Krashan's technical insight, he still doesn't grasp:

1) how an aircraft's engine works
2) the wheel

Jatro13th
02-28-2006, 12:09 AM
Patiently waiting for teh mods to lock it...

Too bad, it has been one hell of a fishing thread.

http://www.jou.ufl.edu/pubs/communigator/fall2002/images/02-Wellborn-fishing.jpg

NonWonderDog
02-28-2006, 12:26 AM
Originally posted by KrashanTopolova:
Airspeed and groundspeed are, for all intents and purposes, the same when an aircraft is travelling on the ground.

No, they are not.

I'll repeat:

NO, they are NOT!

Have you ever heard of a little thing known as wind? Have you ever seen or read about the Fieseler Storch (which is in the sim...), which had such an absurdly low stall speed that it could take off with nearly ZERO groundspeed in a strong headwind?

Groundspeed is inconsequential to everything, and I mean *EVERYTHING*, except time enroute and drift in navigation. Groundspeed has NO other use in aeronautics... not a ONE! Groundspeed means *NOTHING* during takeoff, except how quickly you run out of runway!

rnzoli
02-28-2006, 01:25 AM
http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif Krashan is fishing now, 100% sure. Relax boys, no offending statements please!

The worst thing that can happen to his thread that it sinks to page 2 or 3 without mod lock.

Let us leave Krashan and his babbling in his self-imposed mental prison.

major_setback
02-28-2006, 02:02 AM
I think this is one for 'Mythbusters'.

- (I mean the conveyor belt argument).

Important variations to that question:

What if the Conveyor belt was on a fast moving carrier?

What if the conveyor belt was bolted to the plane!!!!!!

msalama
02-28-2006, 02:07 AM
Hey, this is a good thread http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

major_setback
02-28-2006, 02:57 AM
Originally posted by major_setback:
I think this is one for 'Mythbusters'.

- (I mean the conveyor belt argument).

Important variations to that question:

What if the Conveyor belt was on a fast moving carrier?

What if the conveyor belt was bolted to the plane!!!!!!


I'll reply to myself http://forums.ubi.com/images/smilies/blush.gif

What if the carrier was very, very long and moving fast in the opposite direction to the plane. Would the plane take off if the carrier could keep pace with it?

rnzoli
02-28-2006, 03:09 AM
Originally posted by major_setback:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by major_setback:
I think this is one for 'Mythbusters'.

- (I mean the conveyor belt argument).

Important variations to that question:

What if the Conveyor belt was on a fast moving carrier?

What if the conveyor belt was bolted to the plane!!!!!!


I'll reply to myself http://forums.ubi.com/images/smilies/blush.gif

What if the carrier was very, very long and moving fast in the opposite direction to the plane. Would the plane take off if the carrier could keep pace with it? </div></BLOCKQUOTE>

I don't see your reply.

Z4K
02-28-2006, 03:12 AM
major_setback: You serious?

Because you basically just wrote the original question, but with "conveyor" spelled C - a - r - r - i - e - r.

Also, the implied starting conditions are different, but not so as to make a fundamental change to the question.

_____________________

Also, Krashan's fishing looks, considering his demonstated failure to grasp basic physics and common sense (http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/5961027314/r/6511096514#6511096514), a lot like a trick I used to try. When I was 6.

When proved embarrassingly wrong, instead of admitting it I'd ham it up and pretend that "I knew the right answer all alonghahaha. I was only jokinghahaha. Joke's on you for not realising thathahaha."

It rarely worked.

rnzoli
02-28-2006, 03:17 AM
Originally posted by Z4K:
You serious?

Because you basically just wrote the original question, but with "conveyor" spelled C - a - r - r - i - e - r.

Also, the implied starting conditions are different, but not so as to make a fundamental change to the question.

By the way, one difference: the conveyor belt is 'infinite', while the carrier has a limited length. Which makes me interested how long that carrier should be, if we assume wind=0 and wheel friction negligable. 2 times the distance of the normal takeoff distance for the specific airplane?

Z4K
02-28-2006, 03:26 AM
rnzoli:

True. I read "very, very long" as "sufficiently long as to render worrying about the locations of the ends unneccessary."

The carrier would need to be (if the plane starts off stationary - not relative to carrier):

<pre class="ip-ubbcode-code-pre">carrier_length = (normal_take-off_distance) + (carrier_speed * duration_of_takeoff_roll)</pre>

Cajun76
02-28-2006, 04:03 AM
One more time... and I admit I was fooled for a bit...


Thrust opposes drag.

Do free spinning wheels produce more drag than the thrust of an aircraft engine? If not, then the aircraft moves forward, gains airspeed and takes off.

Ground speed only affects take off distance on the ground. An aircraft can take off with the wind to it's back, it just requires more runway, not more airspeed. It's ground speed will be higher.

http://img.photobucket.com/albums/v30/Cajun76/p38-11.jpg

According to Krashan's logic, if this P-38 were on a long sheet of ice floating on the ocean, as it tried to take off the ice would slip out from underneath like a kid trying to start sprinting on a skateboard due to the skis pressing against the ice.

But what actually happans is that the P-38 takes off, with the ice moved bachwards a bit by the wind off the props, not the skis.

I guess this P-40 won't fly either, will it Krashan?

http://img.photobucket.com/albums/v30/Cajun76/p40-3.jpg

rnzoli
02-28-2006, 04:33 AM
Originally posted by Cajun76:
I guess this P-40 won't fly either, will it Krashan?

http://img.photobucket.com/albums/v30/Cajun76/p40-3.jpg

What's this for? Taking off from swamps? http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

major_setback
02-28-2006, 04:41 AM
Originally posted by rnzoli:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by major_setback:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by major_setback:
I think this is one for 'Mythbusters'.

- (I mean the conveyor belt argument).

Important variations to that question:

What if the Conveyor belt was on a fast moving carrier?

What if the conveyor belt was bolted to the plane!!!!!!


I'll reply to myself http://forums.ubi.com/images/smilies/blush.gif

What if the carrier was very, very long and moving fast in the opposite direction to the plane. Would the plane take off if the carrier could keep pace with it? </div></BLOCKQUOTE>

I don't see your reply. </div></BLOCKQUOTE>

I meant quoted.

major_setback
02-28-2006, 04:55 AM
Originally posted by Z4K:
major_setback: You serious?

Because you basically just wrote the original question, but with "conveyor" spelled C - a - r - r - i - e - r.

Also, the implied starting conditions are different, but not so as to make a fundamental change to the question.

_____________________



That was the point!

Z4K
02-28-2006, 04:57 AM
Whew. Couldn't tell for a minute there. Given the smarts of some of the people in this thread, can you blame me? http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Philipscdrw
02-28-2006, 05:32 AM
This thread is pure comedy gold. If the 'Numa Numa' kid can appear on 'TV's 100 Funniest Moments' (which he did) then this thread is a certain contender... The worst thing about this thread is that several people don't understand the quote-tag system...

The aircraft wouldn't take off, by the way. The aircraft takes off at (say) 100mph, so the pilot applies full-throttle and accelerates towards that speed. But the belt accelerates in the opposite direction, so the difference in speed between the axles of the wheels and the belt is 200mph, which is more than the tyres are designed to take. The tyres overheat and burst, and the aircraft drops onto its undercarriage struts, which dig into the belt and flip the aircraft onto its back.

rnzoli
02-28-2006, 05:53 AM
Originally posted by Philipscdrw:
The worst thing about this thread is that several people don't understand the quote-tag system....

Just one, and it's no accident.


Originally posted by Philipscdrw:
which is more than the tyres are designed to take. The tyres overheat and burst,


Proof? All aircraft systems are built with failure tolerance factors, sometimes greater than 2. The 200 mph is just temporary, at the end of the takeoff roll, so no sufficient heat will build up to burst the tires. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Jatro13th
02-28-2006, 09:23 AM
Hey guys, this reminds me of the Monty Python Argument Clinic:

Man: Is this the right room for an argument?
Other Manhttp://forums.ubi.com/groupee_common/emoticons/icon_frown.gifpause) I've told you once.
Man: No you haven't!
Other Man: Yes I have.
M: When?
O: Just now.
M: No you didn't!
O: Yes I did!
M: You didn't!
O: I did!
M: You didn't!
O: I'm telling you, I did!
M: You didn't!
O: (breaking into the developing argument) Oh I'm sorry, is this a five minute
argument, or the full half hour?
M: Ah! (taking out his wallet and paying) Just the five minutes.
O: Just the five minutes. Thank you.
Anyway, I did.
M: You most certainly did not!
O: Now let's get one thing perfectly clear: I most definitely told you!

And so on, and so on...

Keep up the good work!

rnzoli
02-28-2006, 09:33 AM
Believe it or not, the above conversation was already mentioned in the original thread http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Must be true! http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

DaimonSyrius
02-28-2006, 09:38 AM
Originally posted by Jatro13th:
Hey guys, this reminds me of the Monty Python Argument Clinic:
Hahahha so true! http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

For an even more complete transcription (and equally well related to a comment on the wildlife in these forums) of that sketch, see this post by Loki-PF (http://forums.ubi.com/eve/forums/a/tpc/f/63110913/m/7831035453/r/1941093553#1941093553) on ORR a few months ago http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif http://forums.ubi.com/images/smilies/25.gif

Cheers,
S.

DaimonSyrius
02-28-2006, 09:42 AM
Originally posted by rnzoli:
Believe it or not, the above conversation was already mentioned in the original thread http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Must be true! http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif
That goes to show how, actually, this is the right room for a circular argument !!

http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Cheers,
S.

DoubleTap2005A
02-28-2006, 09:50 AM
Just a question:

Is the conveyor belt blue?

Jatro13th
02-28-2006, 09:59 AM
*Raving mode on*

I think its blue with pink elephants on it.

The elephants add weight to the conveyor, which is transmitted to the plane via the pixies (I dont know, I kinda liked that word and I keep repeating it) and so the inertial mass of the plane exceeds that of a stationary whale, and so the plane stays stuck to the ground, which, by the by, is so fertile that causes the vegetation to grow so rapidly it catches the planes wheels adding friction to this absurd equation!!!

Raving mode off.

DaimonSyrius
02-28-2006, 10:29 AM
Originally posted by Jatro13th:
*Raving mode on*
But... is the whale a free-wheeling whale, or is it rather that whale-sized wheels are acting on their own free-will...?

Somehow, my "Raving mode off" button isn't working... not out of its own free will, anyway, so I'll need a whale-sized, less ill-willed one, maybe http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

Cheers,
S.

Jatro13th
02-28-2006, 10:57 AM
God, I bet that Krashan is somewhere in a place dark, humid, quiet and sinister, rubbing his hands together in satisfaction of the chaos he provoked in our poor little heads... http://forums.ubi.com/images/smilies/59.gif

*Raving mode on*

If my grandma had wheels, then she would be a skateboard! On the other hand, if she was equipped with male genitalia, then she would be my grandpa.
She sells sea shells on the sea shore, and the sea shells she sells on the seashore are sea shells I'm sure.

If we gather the afore mentioned statements we can deduce the logical conclusion that the conv belt which turns with the velocity of a seashell on the planes rudder fin, is not going to reach the critical pH of 3 (acidic) in order to be able to deliver its momentum to my grandma. This enables us to say with certainty that the plane will buckle on to my grandpa's skateboard right next to the sea shore and she who sells the rudder fin's sea shells WILL NEVER TAKE OFF!

There! I think this answers our question in full! Krashan, I give it to you, you win!

*Raving mode ON*

P.S. This is probably my last post in the thread, since it's getting out of hand. I'll try to refrain from posting again, and let the wound itch... it will get better soon... I guess...

DaimonSyrius
02-28-2006, 11:17 AM
Originally posted by Jatro13th:
Krashan, I give it to you, you win!
I see it differently.

We win (if anything would be to be won here) by a sillilly huge silly stretch http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

Cheers,
S.

major_setback
02-28-2006, 11:33 AM
Originally posted by Philipscdrw:

______________________________________________


The aircraft wouldn't take off....
....the difference in speed between the axles of the wheels and the belt is 200mph, which is more than the tyres are designed to take. The tyres overheat and burst, and the aircraft drops onto its undercarriage struts, which dig into the belt and flip the aircraft onto its back.

______________________________________________



You could replace the wheels with skis if there's a risk of the wheels overheating. You'd need a good lubricant though, and the plane would have to start first; with the belt's speed then adjusted to match the foreward speed of the plane.

mmm....it should take off then...or? http://forums.ubi.com/images/smilies/blink.gif

http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Jatro13th
02-28-2006, 01:55 PM
couldn't resist myself in the end... I promise this is my last post in the thread:

Quote from Daimon:
"But... is the whale a free-wheeling whale, or is it rather that whale-sized wheels are acting on their own free-will...?

Somehow, my "Raving mode off" button isn't working... not out of its own free will, anyway, so I'll need a whale-sized, less ill-willed one, maybe Happy"

What? We have a whale that's on wheels and doesn't act on its own free will?
Then the answer to the riddle is only one:

FREE WILLY!!!!!!! FREE WILLY!!!!!!!!!!

http://www.montereybay.com/creagrus/Orca-mty-leap-leohallford.jpg
http://www.guiafe.com.ar/fotos/orca.jpg

Burnzoire1
02-28-2006, 03:27 PM
http://www.hhgttgonline.com/graphics/thumb_petunias_original.gif

KrashanTopolova
02-28-2006, 04:25 PM
Originally posted by Cajun76:
One more time... and I admit I was fooled for a bit...


Thrust opposes drag.
_____________________________________________
Wrong: drag naturally increases trying to equal thrust.
If it equals thrust in certain conditions then there is a terminal velocity (no more acceleration)
_____________________________________________

Do free spinning wheels produce more drag than the thrust of an aircraft engine? If not, then the aircraft moves forward, gains airspeed and takes off.
____________________________________________
you are forgetting or not understanding that there are other forces applying such as the normal force acting upward (force applied by ground upon a mass) and a gravity force leading to weight at a certain position on earth (acting downwards).
These are just some of the forces beside friction coefficients that act upon the aircraft rolling quite silly on a conveyor belt
_______________________________________________
____________________________________________

Ground speed only affects take off distance on the ground. An aircraft can take off with the wind to it's back, it just requires more runway, not more airspeed. It's ground speed will be higher.
_____________________________________________
wrong: wing loading affects rotation (velocity) and length of takoff roll length...its grondspeed can remain the same; that's why an aircraft can takeoff with a tailwind...the lift coefficient is the important factor. But the turbulence that may be caused by a tailwind can be dramatic.
Groundspeed is a scalar quantity that can be used to factor force vector quantities (eg add or multiply it). Thus tailwind of 30Knots x velocity of aircraft from its own power = less takeoff roll distance if and when rotation speed is reached.
______________________________________________
_____________________________________________

http://img.photobucket.com/albums/v30/Cajun76/p38-11.jpg

According to Krashan's logic, if this P-38 were on a long sheet of ice floating on the ocean, as it tried to take off the ice would slip out from underneath like a kid trying to start sprinting on a skateboard due to the skis pressing against the ice.

But what actually happans is that the P-38 takes off, with the ice moved bachwards a bit by the wind off the props, not the skis.

I guess this P-40 won't fly either, will it Krashan?
______________________________________________
Yes it will...its got skis to handle the ice.
______________________________________________

http://img.photobucket.com/albums/v30/Cajun76/p40-3.jpg

Davinci..
02-28-2006, 05:03 PM
Originally posted by KrashanTopolova:
Groundspeed is a scalar quantity that can be used to factor force vector quantities (eg add or multiply it). Thus tailwind of 30Knots x velocity of aircraft from its own power = less takeoff roll distance if and when rotation speed is reached.


not only is this wrong, it is the complete opposite of what is true.. Everything you state as a fact to use as an argument, is so horribly wrong, it is the opposite of what is real..

we cannot help you.

Treetop64
02-28-2006, 05:22 PM
Originally posted by KrashanTopolova:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Burnzoire:
whilst you're at it, take a look at those gauges I posted... note none of them show GROUND speed. It's a pretty safe assumption to use airspeed for the speed of an airplane - you you've chosen ground speed and ignore the fact that everyone else in the universe is talking about air speed. AIR speed man, we're talking abotu an aircraft not a car!

______________________________________________
airspeed is measured by pressure differentials thrpough the pitot tube...it depends on measures such as air pressure at sea level and air pressures at altitude.
Airspeed and groundspeed are, for all intents and purposes, the same when an aircraft is travelling on the ground. The istuation changes only when the aircraft becomes airborne
________________________________________________ </div></BLOCKQUOTE>

Amazing. Absolutely amazing... http://forums.ubi.com/images/smilies/51.gif

Hey Krashan. See those nice people over there in the corner, in the white coats, all looking at you intently? See them? Those are your new friends, Krashan. They are really nice folks, and they will take real good care of you, okay?

KrashanTopolova
02-28-2006, 06:19 PM
Alright..it seems some of you are having difficulty with this 'puzzle'...

I've just been thinking: if those responding promptly to my posts live overseas then they are staying awake waiting to jump on me...I can see them now, toothpicks propping up eyelids...
Maybe this explains some of the weird answers from them recently.

Nevertheless;

We all, I presume, are familiar with Bernoulli's explanation of how an airfoil works (pressure differentials between top and bottom of wing...yes?)

But as physicists David Anderson and Scott Eberhard recently challenged; Bernoulli's way is not the only way to understand flight.

Rather, they say, flight from an airfoil is quite simple: it is a reaction force as described by Newton's 3rd (for every action there is an equal and opposite reaction). That is; the wing can be seen to be simply pushing the air down, so in turn the air pushes the wing up. The two explanations produce the same equations - it's only the imagery that is different.

So now we could - if we chose - see that everything in this 'puzzle' may be explained purely in terms of Newton's laws of force.
And it all boils down to whether or not the airfoil:
1. moves through the air while on the conveyor belt.
2. gains sufficient energy to invoke the force required to produce lift.

In contrast to the emotional output from the conveyor belt flyers I have logically dispensed with those arguments...neither 1 nor 2 arise.

But curiously, the conveyor belt flyers, having spent too much time flying with pixies have ignored one factor of the conveyor belt that 'might' produce lift without the need for sufficient velocity of the airfoil through the air mass...


I will give you some chances to tell or guess what it might be...
_______________________________________________
'...scientists have discovered a noise made just prior to the Big Bang which sounds something like 'Oops'...'
_______________________________________________

Davinci..
02-28-2006, 06:46 PM
Originally posted by KrashanTopolova:

But as physicists David Anderson and Scott Eberhard recently challenged; Bernoulli's way is not the only way to understand flight.

Rather, they say, flight from an airfoil is quite simple: it is a reaction force as described by Newton's 3rd (for every action there is an equal and opposite reaction). That is; the wing can be seen to be simply pushing the air down, so in turn the air pushes the wing up. The two explanations produce the same equations - it's only the imagery that is different.


Wrong...

first off, its nothing new.. It is well known that deflection can "add" to the lift generated by an airfoil. This is not new, They are not the same thing(just different images), they are completly different principles.. the 2 "equations" are not the same, and CANNOT produce the same results.

this is why wings are curved(we call it camber), and not just giant flat surfaces, If that was really all that was needed(as your post clearly states, and is wrong). There is a reason you cannot simply strap a pair of barn doors to your car and go flying(which oddly enough your posts state as possible).

again you are wrong.

The majority of lift is produced by the pressure differential..

quick summary:

you: planes move forward because thrust is delieverd through friction contact between the ground and its wheels.

you: a plane can only take off when it reaches a certain speed over the ground.

you: you do not need wings to fly, only flat surfaces capable of deflecting air downwards to create lift.

which is funny because, i would expect to look out my window right now, and see cars with sheets of plywood strapped to them flying all around. But for some reason i dont.. but in your mind this is completly possible..

Burnzoire1
02-28-2006, 06:46 PM
for crying out loud we're all aware of "bernoulli's way"

The plane WILL get speed to produce the erquired lift, but you keep ignoring our explanations and instead go off into scientific tangents that are mostly incorrect and always have NOTHING to do with what we just said.

The propeller/Jet propells the aircraft forward thus reaching speeds to produce lift. The propeller/jet does NOT get magically held back by spinning wheels.

BillPosters
02-28-2006, 07:18 PM
Originally posted by KrashanTopolova:
And it all boils down to whether or not the airfoil:
1. moves through the air while on the conveyor belt.
2. gains sufficient energy to invoke the force required to produce lift.

In contrast to the emotional output from the conveyor belt flyers I have logically dispensed with those arguments...neither 1 nor 2 arise.



AAAAAAAAARRRRRRRRRRRGGGGGGGGHHHHHHHH!!!!!!!!!

1. The plane moves forward throught the *air*.

2. The conveyor belt moves backwards at the same speed (but opposite direction).

3. The wheels spin crazily trying to make up for the difference between the two.

4. The plane flies.

5. Krashan realises this and continues to troll anyway (my sanity relies on this assumption).

danjama
02-28-2006, 07:25 PM
i just want to be in this thread

+1

tonyt1960
02-28-2006, 08:02 PM
46 pages of real pilots debating this issue, enjoy! (http://forums.flightinfo.com/showthread.php?t=66860&highlight=conveyor+belt)

Davinci..
02-28-2006, 08:25 PM
Originally posted by tonyt1960:
46 pages of real pilots debating this issue, enjoy! (http://forums.flightinfo.com/showthread.php?t=66860&highlight=conveyor+belt)

heh same basic thing happend here.
.
at first it tricks everyone, then quickly people realize the wheels spin independently of the plane, and thus the friction in the wheels cant stop it, and it will take off. eventually everyone gets it, and it all makes sense.

but of course 1 person, dose not want to admit they could be wrong, so fights long and hard, while everyone else knows the right answer, and knows the guy is just putting up a fight because he will not admit he is wrong, though he probably knows he is.

Cajun76
02-28-2006, 08:57 PM
Originally posted by Jatro13th:
Hey guys, this reminds me of the Monty Python Argument Clinic:

Man: Is this the right room for an argument?
Other Manhttp://forums.ubi.com/groupee_common/emoticons/icon_frown.gifpause) I've told you once.
Man: No you haven't!
Other Man: Yes I have.
M: When?
O: Just now.
M: No you didn't!
O: Yes I did!
M: You didn't!
O: I did!
M: You didn't!
O: I'm telling you, I did!
M: You didn't!
O: (breaking into the developing argument) Oh I'm sorry, is this a five minute
argument, or the full half hour?
M: Ah! (taking out his wallet and paying) Just the five minutes.
O: Just the five minutes. Thank you.
Anyway, I did.
M: You most certainly did not!
O: Now let's get one thing perfectly clear: I most definitely told you!

And so on, and so on...

Keep up the good work!

http://img.photobucket.com/albums/v30/Cajun76/yesno.gif

tonyt1960
02-28-2006, 09:01 PM
I didnt read all the posts, so forgive me if someone already covered this...

For those that dont believe it will take off, picture this...

A rope is tied to the spinner of the aircraft. Pretend there is a swivel hook in the center of the spinner which prevents the rope from twisting. The plane is on a conveyor belt. The other end of the rope is tied to your car. Like this...

Plane spinner<-------------rope--------------->car

Your car is on solid ground while the plane being on the conveyor belt. As you start the conveyor belt motor to spin the belt, you remain stationary in your car (which is tied to the plane), so the plane also remains in place while the belt spins underneath. Spin the belt as fast as it can go, will the plane remain in place? Now, hit the gas on your car while having some sort of device to measure the plane speed so the belt can match speed. With the plane still tied to your car, and your car being on solid ground, will the plane remain in place when you hit the gas on your car? Or will your car pull the plane forward regardless of conveyor belt speed.

PS. I especially got a kick out of Krashan saying a tailwind shortens take off roll. I have a feeling he may be baiting you guys. No one can be that ignorant... could they?

Cajun76
02-28-2006, 09:03 PM
I can't take much more, Krashan...

http://img.photobucket.com/albums/v30/Cajun76/Frustration01.gif

http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Davinci..
02-28-2006, 09:24 PM
hot diggidy.

here Karahan
argue with this..

http://videos.streetfire.net/player.aspx?fileid=35E964D...FD-BE8D-D6BA1A43A06B (http://videos.streetfire.net/player.aspx?fileid=35E964D9-38DB-4EFD-BE8D-D6BA1A43A06B)

note: he tries to mimic the scateboards speed with the speed at which he pulls the "conveyor" out from under it..

but also note: no matter how fast(within reason) he ripps it out from under the skateboard.. the wheels would just spin twice as fast..

i know your just going to argue semantics about speed matching and or something else, so i dont expect you to admit your wrong, but this ought to knock some sense into ya.. if you can see it with your owns eyes, you dont have to admit it, but at least you'll know..

Cajun76
02-28-2006, 10:00 PM
I'll use just one here to blow a huge hole...

I asked:

Do free spinning wheels produce more drag than the thrust of an aircraft engine? If not, then the aircraft moves forward, gains airspeed and takes off.
____________________________________________

Krashan replies:

you are forgetting or not understanding that there are other forces applying such as the normal force acting upward (force applied by ground upon a mass) and a gravity force leading to weight at a certain position on earth (acting downwards).
These are just some of the forces beside friction coefficients that act upon the aircraft rolling ....


I reply:

That dosen't apply to an aircraft sitting on a normal runway? "the normal force acting upward (force applied by ground upon a mass) and a gravity force leading to weight at a certain position on earth (acting downwards)" prevents them from moving?


So tell me, what is preventing the engine from overcoming the free spinning wheels? Ineria? A/c do it all the time. Ground friction? Engines overcome it all the time.

The C-130's I work on can "jump chocks" if you don't follow procedure, and that's including locking the brakes. If a C-130 can drag itself over wheel chocks with the brakes locked, what prevents it from running down a runway, moving or not, with the wheels free spinning?

It's powered past inertia, drag, friction, even "the normal force acting upward (force applied by ground upon a mass) and a gravity force leading to weight at a certain position on earth (acting downwards)". The friction between the wheels and the moving runway are negligeble compared to the power being produced. Just because the conveyer matches the aircraft's speed has nothing to do with it.



http://forums.ubi.com/images/smilies/35.gif CZECH THIS OUT> http://forums.ubi.com/images/smilies/35.gif Same net conditions and result. The a/c is on a runway of roller bearings. The wheels of the a/c are controlled in such a way that the speed of the aircraft determines how fast the wheels of the plane are rotated backward. The dang thing will still takeoff, with the wheels spinning 2x as fast. This is the same problem as before, but now the wheels act like the conveyer would, the the bearing runway acts as the free spinning wheels.

Get it?

Sheesh....

http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Burnzoire1
02-28-2006, 11:09 PM
What gets me is krashan's aggressive approach. He thinks *we're* the ones staying up all night waiting for a response... but what about him? He started the thread as an attempt to make fun of all those people who think the aircraft will take off. As if the other thread didn't go on long enough, he starts another with this aggressive title. So who's obsessive here?

Stafroty
02-28-2006, 11:26 PM
there isnt enought information to solve that riddle http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Burnzoire1
03-01-2006, 12:02 AM
sure there is.

the point of the riddle is that the conveyor belt's speed is largely irrelevant. It's just a trick to get you thinking along the lines of cars on a conveyor, or people on a tread mill. It's very effective at that http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Once you get past that train of thought, you must realise that the wheels spin on their axis with the conveyor, but the aircraft still physically moves forward due to the engine (any conventional aircraft engine) will grab the air and propell the aircraft forward. There is nothing in the riddle that needs to be clarified here, for most of it is just a trick...

Aircraft + conveyor belt. The rest is history http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

If it were car + conveyor belt then we'd have a totally different problem.

DaimonSyrius
03-01-2006, 12:12 AM
Originally posted by Burnzoire:
So who's obsessive here?

Originally posted by Stafroty:
there isnt enought information to solve that riddle http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Originally posted by Burnzoire:
sure there is
the point of the riddle is that the conveyor belt's speed .../...
If I'm understanding this correctly, Stafroty was actually referring to your last question. In that case, your own confusion would be proving the point http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Isn't this thread endless fun? http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

Cheers,
S.

Burnzoire1
03-01-2006, 02:10 AM
heheh you may be right, I don't know :S Confused indeed... I think I've explained the answer about 10 times so far, I think that'll do http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

It's all good fun though! It's a puzzle that has the whole internet arguing http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

rnzoli
03-01-2006, 02:53 AM
Originally posted by Cajun76:
I can't take much more, Krashan...

http://img.photobucket.com/albums/v30/Cajun76/Frustration01.gif

http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

This thread keeps me amused every day! http://forums.ubi.com/images/smilies/88.gif


NB. Once again, no personal offenses, PLEASE, from either side. The worst thing I can imagine is that some people loose their composure, the topic gets locked, and next day a new thread is launched about the same thing, from the very beginning! http://forums.ubi.com/images/smilies/53.gif

KrashanTopolova
03-01-2006, 05:13 PM
Geez you fellas are obstinate...!

do you understand physics at all...?

try this:
Terms:
v = velocity
t(i) = initial velocity
t(1)....t(x) = any velocity after t=0


If at t(i), v=0 (because the aircraft is idling on the conveyor and there is no velocity because there is no direction in existence until the aircraft starts moving on the conveyor belt and thus adds a direction vector to your 'speed' to become velocity...how many times do I have to repeat these things...)?

then:
since the conveyor is under the condition of keeping up with the aircraft 'speed' (see I do listen!...whether this is practically possible from the conditions or not and whether you see v as airspeed or pixies pulling)

then: clearly at t(1).....(tx) v = 0 indefinately because the belt keeps up with the aircraft 'speed' (as you put it)...

there is no forward momentum or if there is it is going into equilibrium far below rotation speed. It never flies unless...


In fact the aircraft has more chance of flying from the ground effect brought into existence by the turbulence caused by the elevator than it does from the propellor or jet engine alone...

If you don't understand ground effect then you are no pilot.

I don't believe a film just because it purports to show evidence...have a good look at a real jet fighter when it goes full throttle from stand by...there's no pixies there making it accelerate real fast...if there are then those particular pixies are FAT because all jet fighters lumber into a take-off roll like all normal horizontal thrust aircraft.


BTW you fellas keep taking me out of context and keep responding with no proof...

do better please...and get some sleep...you are all raving!

Burnzoire1
03-01-2006, 05:33 PM
Originally posted by KrashanTopolova:
then: clearly at t(1).....(tx) v = 0 indefinately because the belt keeps up with the aircraft 'speed' (as you put it)...

there is no forward momentum or if there is it is going into equilibrium far below rotation speed. It never flies unless...


Again, you seem to think the belt's speed will affect an aircraft on wheels. This is not a physics problem, it's a logical problem that you're consistantly failing. The belt can keep up with the aircraft all it wants but
IT WILL NOT STOP THE AIRCRAFT FROM PROPELLING ITSELF FORWARD.

I haven't read a single sentence from you that explains how this is incorrect. All I'm hearing is your rude, closed mind blabbing about formulae that ignore the fundamental point in this whole puzzle. If you can't explain your answer simply, you're just fooling yourself.

Burnzoire1
03-01-2006, 05:51 PM
as far as the 'lumbering' into takeoff roll comment, the only thing the engine needs to overcome is the initial friction involved with the aircraft's mass on the bearings of the wheel, possibly also from the tyre will cause very slight resistance starting from a stand still. The conveyor only moves when the aircraft does remember, so to begin with it's just a very slow moving conveyor belt with only effects the aircraft with minimal bearing resistance. One those wheels are spinning any friction is completely neglegible. After that the aircraft picks up speed as does the conveyor, which as I've said a hundred times, doesn't increase the rearward force at all - the aircraft is on wheels!

Like someone said earlier, if an aircraft can jump it's chocks with brakes on, you're not going to have any problems with a slowly accelerating conveyor belt. No formulae needed mate. Use your common sense and get your head out of the physics books, because none of your reasoning can explain how wheel friction can stop an aircraft in it's tracks.

BillPosters
03-01-2006, 06:11 PM
Originally posted by KrashanTopolova:
then: clearly at t(1).....(tx) v = 0 indefinately because the belt keeps up with the aircraft 'speed' (as you put it)...


Here is where you are mistaken.

The conveyor does keep up with the aircraft at a velocity that is equal in speed and opposite in direction to the aircraft.
However, the movement of the belt *does not* effect the velocity of the aircraft in any significant way.
v is unrelated to the belt movement. Therefor the aircraft is free to increase its velocity and take off.

It's like taking 2 pieces of paper and rubbing them together. Both at the same speed but in opposite directions. There will be friction but both will keep moving.
By your logic they would never move. Nothing ever would.

Your arguments consist of increasingly complicated ways of saying:

Step 1: Belt matches planes speed.
Step 2: ???
Step 3: No take off.

<span class="ev_code_RED">Forget the overly elaborate explanations of physics and explain to us precisely why you think the movement of the conveyor belt will affect the velocity of the aircraft.</span>

If you do not address this exact point then I will be finally convinced that you are doing nothing but trolling the forum and I'll finally be able to stop posting in this trainwreck of a thread.

Cajun76
03-01-2006, 07:29 PM
Originally posted by KrashanTopolova:


then: clearly at t(1).....(tx) v = 0 indefinately because the belt keeps up with the aircraft 'speed' (as you put it)...


Yes, the belt keeps up with the a/c speed. However, it imparts no velocity to the aircraft because it is interacting with free spinning wheels.

Your even allowing that the a/c might be moving, but can't get get sufficient velocity to take off. Again, how are free spinning tires ******ing this accelaration?

Read the last part of my last post, I flipped the way the tires and runway interact while preserving the conditions of the question.

I think I'm done though. Just please never take up real flying, aviation has a pretty good safety record so far... http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

Jatro13th
03-02-2006, 12:46 AM
Initial conditions:

Speed of air in relation to the ground = 0
Speed of plane in relation to ground & air = 0
Speed of belt in relation to ground = 0
speed of plane in relation to belt = 0
Speed of wheels in relation to belt = 0

at rotation

Speed of air in relation to ground = 0
Speed of plane in relation to ground & air = Vr
Speed of belt in relation to ground = -Vr
Speed of plane in relation to belt = 2xVr
Speed of wheels in relation to belt = 2xVr

All the rest is nonsense and won't convince me in any way.

Krashan get a grip, fishing is over, you'll empty the river soon.

P.S.

Krashan, you said:
then: clearly at t(1).....(tx) v = 0 indefinately because the belt keeps up with the aircraft 'speed' (as you put it)...

WTF????????? ROFLMAO!!!!!!! Where do you come up with such nonsense? What is that? If you wrote something like this in an physics exam you would have your ears boxed! So now, the belt incorporates the ground and the air surrounding it and it has the same and co-directional speed with the plane at all times?????????????????????
http://forums.ubi.com/images/smilies/34.gif http://forums.ubi.com/images/smilies/34.gif http://forums.ubi.com/images/smilies/11.gif http://forums.ubi.com/images/smilies/11.gif http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/88.gif

KrashanTopolova
03-02-2006, 03:59 PM
Get my head out of physics...? http://forums.ubi.com/images/smilies/53.gif

Would Newton have said that to Galileo or Einstein to Newton...?

How can I get this through into your heads..?

Speed is a scalar...SCALAR...spelt S.k.a.y.l.a.a.
This means Speed is measured by a quantity eg MPH or KMH...
The wheels can measure displacement because they have a measurable circumference but they can't measure displacement without having a direction...as say a perambulator...spelt: (well mever mind that)

The wheels can have any Speed until they burst apart... but like your arguments they are going nowhere without direction...(think of a couple of pixies holding the handles of a wheelbarrow on a conveyor so that only the wheel spins on the conveyor at say 30 pixels per frame of ntrk)...(Geez I think I need some sleep)...


When the wheels have a direction vector to the speed, speed changes into velocity...which is a Vector...VECTOR...spelt v.e.c.k.t.a...! and it is the time rate of change of Position...

Therefore a body has a unit velocity when it moves at the rate of unit length in unit time...L...T...-1

without velocity there is no acceleration possible but acceleration can erode back into velocity...which can erode back into speed when one is lost and unable to follow simple directions.

Now consider a problem where a low-powered gun is fired in an enclosed aircraft where there is no air resistance etc to impede the momentum of the bullet.
The tail gunner wants to get back at the pilot for leaving him on the runway at landing training once and so fires at him as the aircraft is doing (say) 200 knots. Now that bullet would have the momentum of 200 knots added to it...yes?
Now consider if the pilot fired back at the tail gunner because the tail gunner complained too much about his flying.
If the speed of the bullet were equal to the opposite speed of the plane it would drop to the floor of the aircraft as soon as it emerged from the muzzle because both speeds detract from each other.

The same is occurring on the conveyor belt...

p-11.cAce
03-02-2006, 04:32 PM
ok I'll bite on this one:
http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif WTF?

The tail gunner wants to get back at the pilot for leaving him on the runway at landing training once and so fires at him as the aircraft is doing (say) 200 knots. Now that bullet would have the momentum of 200 knots added to it...yes?
http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif Ok its time to introduce this little item that perhaps is the key to your misunderstandings - RELATIVITY. The bullet will not have 200 knots added to its velocity in relation to the pilot or the tailgunner - they and everything else inside the plane are moving at 0knots relative to each other (assuming that all above mentioned are not moving about the aircraft). Now in relation to an outside stationary observer the bullet will have 200 knots added to its velocity (assuming you are talking about 200 knots across the ground and NOT 200 knots airspeed - if the aircraft is flying at 200 knots indicated directly into a 200 knot wind the ground speed is 0knots and the bullet will have 0 knots added to its speed relative to said outside observer. Krash you are the best fisherman I know!

Burnzoire1
03-02-2006, 04:42 PM
Way to go ignoring everything I've said krashyan!

Yes, get your head out of the physics books, because you're struggling to cope with a problem that you wouldn't find in them.



The wheels on the plane go round and round...

Treetop64
03-02-2006, 05:33 PM
Can someone get the friggin' keys already, please?

http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

Davinci..
03-02-2006, 05:46 PM
Originally posted by KrashanTopolova:
The tail gunner wants to get back at the pilot for leaving him on the runway at landing training once and so fires at him as the aircraft is doing (say) 200 knots. Now that bullet would have the momentum of 200 knots added to it...yes?
Now consider if the pilot fired back at the tail gunner because the tail gunner complained too much about his flying.
If the speed of the bullet were equal to the opposite speed of the plane it would drop to the floor of the aircraft as soon as it emerged from the muzzle because both speeds detract from each other.

The same is occurring on the conveyor belt...

just when i thought you had said the dumbest thing ever.. you kept right on talking..

in your example..
if the aircraft is moving at 200knots, and the tailgunner shoot at the pilot(inside the aircraft), with a gun that shoots at 200knots.
THE VELOCITY DOES NOT ADD. The bullet will travel from the tail gunner to the pilot at 200knots.. as well if the pilot shoots back under the same conditions, the bullet will travel from the pilot to the tailgunner at 200knots(yes with the aircraft still moving at 200knots in the other direction).

you say "the same is occuring on the conveyor belt"

you see this is the(your) problem.. ALL of your "proofs" and arguments are based on FLAWED physics, and as such, are invalid..

This is why we cant answer some of your questions, because the arise from situations that DO NOT happen in the real worl, and why you cant answer our questions, because they dont happen in your phyicsless world..

you cannot argue "the aircraft wont move becasue of this and that", if this and that, arnet true(as in the case of everything you've posted..)

everything you use to hold up your arguments is flat out wrong, your are spectacularly uneducated in physics, motion, and flight. And bringing up Newton or Einstein isnt a good idea, considering you are the complete opposite of them.

BillPosters
03-02-2006, 06:00 PM
Originally posted by KrashanTopolova:
Get my head out of physics...? http://forums.ubi.com/images/smilies/53.gif

Would Newton have said that to Galileo or Einstein to Newton...?

How can I get this through into your heads..?

Speed is a scalar...SCALAR...spelt S.k.a.y.l.a.a.
This means Speed is measured by a quantity eg MPH or KMH...
The wheels can measure displacement because they have a measurable circumference but they can't measure displacement without having a direction...as say a perambulator...spelt: (well mever mind that)

The wheels can have any Speed until they burst apart... but like your arguments they are going nowhere without direction...(think of a couple of pixies holding the handles of a wheelbarrow on a conveyor so that only the wheel spins on the conveyor at say 30 pixels per frame of ntrk)...(Geez I think I need some sleep)...


When the wheels have a direction vector to the speed, speed changes into velocity...which is a Vector...VECTOR...spelt v.e.c.k.t.a...! and it is the time rate of change of Position...

Therefore a body has a unit velocity when it moves at the rate of unit length in unit time...L...T...-1

without velocity there is no acceleration possible but acceleration can erode back into velocity...which can erode back into speed when one is lost and unable to follow simple directions.

Now consider a problem where a low-powered gun is fired in an enclosed aircraft where there is no air resistance etc to impede the momentum of the bullet.
The tail gunner wants to get back at the pilot for leaving him on the runway at landing training once and so fires at him as the aircraft is doing (say) 200 knots. Now that bullet would have the momentum of 200 knots added to it...yes?
Now consider if the pilot fired back at the tail gunner because the tail gunner complained too much about his flying.
If the speed of the bullet were equal to the opposite speed of the plane it would drop to the floor of the aircraft as soon as it emerged from the muzzle because both speeds detract from each other.

The same is occurring on the conveyor belt...

That is the most complicated way of saying "Yes, I am a troll" that I have ever seen.

I'm out. This kind of foolishness frustrates me far more than it should.

KrashanTopolova
03-02-2006, 06:43 PM
velocity and acceleration are vector quantities. As such they are amenable to mathematical operations (even by scalars)...

addition of vectors:

bullet at 200 knots displacing north inside an aircraft at 20 ft above the ground displacing in the exact same direction at 200 knots: bullet travelling at 200 + 200 = 400 knots relative to the ground (or nearest surface subject to the gravitational constant).

subtraction of vectors:
bullet displacing south at 200 knots inside an aircraft displacing north at 200 knots:
200 - 200 = 0v relative to the ground (or nearest surface subject to the gravitational constant)

This is why you can't be shot relatively well by a relative with a gun having a muzzle velocity less than the airspeed of the aircraft if that airspeed is in the exact opposite direction to where the gun is pointing (ignoring all friction and other sources of disturbance). Now if you had a normal gun...

KrashanTopolova
03-02-2006, 06:53 PM
Originally posted by Burnzoire:
Way to go ignoring everything I've said krashyan!

Yes, get your head out of the physics books, because you're struggling to cope with a problem that you wouldn't find in them.

_____________________________________________
you wouldn't find this 'interesting puzzle' as an example in textbook physics either, generally...that's because there is no educative value in the problem as set out...there is no displacement, velocity, acceleration or such. There are however, deeper questions proposed by the 'puzzle' such as torque, turbulence, rotational momentum...all sorts of goodies.

Shall we carry on...?
_____________________________________________



The wheels on the plane go round and round...and foot.pound for foot.pound
it don't get off the ground...

Burnzoire1
03-02-2006, 06:54 PM
so how again does this nonsense apply to a simple conveyor belt?

I dont' see why a "troll" would go to all this effort. I really think you're just thinking WAY too hard about this, and can't handle the fact that there's a much simpler explanation to it. It's a riddle for a reason, but I guess you're the type to argue the colour of the sky to save face, aren't you?

p-11.cAce
03-02-2006, 06:58 PM
yeah - thats exactly what I said.

Now consider if the pilot fired back at the tail gunner because the tail gunner complained too much about his flying.
If the speed of the bullet were equal to the opposite speed of the plane it would drop to the floor of the aircraft as soon as it emerged from the muzzle because both speeds detract from each other. Just please admit that you are wrong here. Please?? You and I both know that the speed of the aircraft is not subtracted from the velocity of the bullet causing it to drop to the floor. In relation to a stationary observer yes the bullet would be stationary but that bullet is going to slam into the tail gunner at 200 knots NOT drop to the floor.

Davinci..
03-02-2006, 07:08 PM
Originally posted by KrashanTopolova:
velocity and acceleration are vector quantities. As such they are amenable to mathematical operations (even by scalars)...

addition of vectors:

bullet at 200 knots displacing north inside an aircraft at 20 ft above the ground displacing in the exact same direction at 200 knots: bullet travelling at 200 + 200 = 400 knots relative to the ground (or nearest surface subject to the gravitational constant).

subtraction of vectors:
bullet displacing south at 200 knots inside an aircraft displacing north at 200 knots:
200 - 200 = 0v relative to the ground (or nearest surface subject to the gravitational constant)

thats all fine and dandy, except you chose an internal frame of refrence(quote: "in an enclosed aircraft")

a bullet fired from the tailgunner to the pilot(your words, your setup, your frame of refrence) will NOT hit the pilot with 200+200knots of "momentum". And a bullet fired the other way will not have "0v"

ill make this VERY easy for you, so easy even you can handle this idea.
someone posted a great explanation on the other forums in this debate(and by debate i mean, people who know what they are talking about, trying to talk sense into someone that dosnt know the difference between airspeed and ground speed).

ok here goes, same basic setup, except...
instead of the aircraft on the conveyor, it is a motorcycle sidecar, with the motorcyle off to the side of it, and NOT on the conveyor.

the conveyor is still rigged to move at the same speed but in the opposite direction as the motorcycle and its sidecar..

does it move???
if you say yes, then you have to concede the aircraft would move as well.

if you say no, then come up with a brilliant explanation, as to how in the world(or in your case, you anti-phyiscs world) it dosnt...

good luck...

KrashanTopolova
03-02-2006, 07:16 PM
Originally posted by p-11.cAce:
yeah - thats exactly what I said.
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Now consider if the pilot fired back at the tail gunner because the tail gunner complained too much about his flying.
If the speed of the bullet were equal to the opposite speed of the plane it would drop to the floor of the aircraft as soon as it emerged from the muzzle because both speeds detract from each other. Just please admit that you are wrong here. Please?? You and I both know that the speed of the aircraft is not subtracted from the velocity of the bullet causing it to drop to the floor. In relation to a stationary observer yes the bullet would be stationary but that bullet is going to slam into the tail gunner at 200 knots NOT drop to the floor. </div></BLOCKQUOTE>

___________________________________________
You may have the idea of a normal gun clouding your conception.

velocity and acceleration are vectors and as such are amenable to mathematical operations.
(even with scalars if the units are amenable)

but here we are talking about SPEED (a scalar).

The bullet travels at (say x) MPH or (x) KmH or (x) knots. It obtains a velocity by travelling in a certain direction for a certain length for a certain time as soon as it leaves the muzzle:

200 knots in an aircraft doing 200 knots in the exact opposite vector:

200 - 200 = 0v relative to the ground or nearest surface subject to the gravitational constant).

BTW. This answer does appear in a textbook...

BillPosters
03-02-2006, 07:21 PM
Originally posted by p-11.cAce:
In relation to a stationary observer yes the bullet would be stationary but that bullet is going to slam into the tail gunner at 200 knots NOT drop to the floor.

Well, you could argue that the tail gunner slams into the bullet at 200 knots but the effect is much the same. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Incidentally, the earth orbits the sun at an average of 29.8km/s. Does this mean that a bullet will dribble out of your gun and land harmlessly on the ground depending on which direction you are facing relative to earths orbit? http://forums.ubi.com/images/smilies/88.gif

KrashanTopolova
03-02-2006, 07:22 PM
Originally posted by Davinci..:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by KrashanTopolova:
velocity and acceleration are vector quantities. As such they are amenable to mathematical operations (even by scalars)...

addition of vectors:

bullet at 200 knots displacing north inside an aircraft at 20 ft above the ground displacing in the exact same direction at 200 knots: bullet travelling at 200 + 200 = 400 knots relative to the ground (or nearest surface subject to the gravitational constant).

subtraction of vectors:
bullet displacing south at 200 knots inside an aircraft displacing north at 200 knots:
200 - 200 = 0v relative to the ground (or nearest surface subject to the gravitational constant)

thats all fine and dandy, except you chose an internal frame of refrence(quote: "in an enclosed aircraft")

a bullet fired from the tailgunner to the pilot(your words, your setup, your frame of refrence) will NOT hit the pilot with 200+200knots of "momentum". And a bullet fired the other way will not have "0v"

ill make this VERY easy for you, so easy even you can handle this idea.
someone posted a great explanation on the other forums in this debate(and by debate i mean, people who know what they are talking about, trying to talk sense into someone that dosnt know the difference between airspeed and ground speed).

ok here goes, same basic setup, except...
instead of the aircraft on the conveyor, it is a motorcycle sidecar, with the motorcyle off to the side of it, and NOT on the conveyor.

the conveyor is still rigged to move at the same speed but in the opposite direction as the motorcycle and its sidecar..

does it move???
if you say yes, then you have to concede the aircraft would move as well.

if you say no, then come up with a brilliant explanation, as to how in the world(or in your case, you anti-phyiscs world) it dosnt...

good luck... </div></BLOCKQUOTE>

______________________________________________
the sidecar would move on the conveyor because it is remotely connected to the motorcycle which has (and only it has) the moment of force to move the sidecar by the agency of power directed against a non-moving surface (the normal ground off the conveyor belt)...
______________________________________________

BillPosters
03-02-2006, 07:25 PM
Originally posted by KrashanTopolova:
the sidecar would move on the conveyor because it is remotely connected to the motorcycle which has (and only it has) the moment of force to move the sidecar by the agency of power directed against a non-moving surface (the normal ground off the conveyor belt)...

the *aircraft* would move on the conveyor because it is remotely connected to the *propeller* which has (and only it has) the moment of force to move the *aircraft* by the agency of power directed against a non-moving surface (the normal *air* off the conveyor belt)...

KrashanTopolova
03-02-2006, 07:26 PM
Originally posted by BillPosters:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by p-11.cAce:
In relation to a stationary observer yes the bullet would be stationary but that bullet is going to slam into the tail gunner at 200 knots NOT drop to the floor.

Well, you could argue that the tail gunner slams into the bullet at 200 knots but the effect is much the same. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif
___________________________________________
the tail gunner does not slam into the bullet unless the momentum of the aircraft is suddenly stopped.
_____________________________________________

Incidentally, the earth orbits the sun at an average of 29.8km/s. Does this mean that a bullet will dribble out of your gun and land harmlessly on the ground depending on which direction you are facing relative to earths orbit? http://forums.ubi.com/images/smilies/88.gif </div></BLOCKQUOTE>
_____________________________________________
No...the bullet then has rotational acceleration
_____________________________________________

BillPosters
03-02-2006, 07:31 PM
Originally posted by KrashanTopolova:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BillPosters:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by p-11.cAce:
In relation to a stationary observer yes the bullet would be stationary but that bullet is going to slam into the tail gunner at 200 knots NOT drop to the floor.

Well, you could argue that the tail gunner slams into the bullet at 200 knots but the effect is much the same. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif
___________________________________________
the tail gunner does not slam into the bullet unless the momentum of the aircraft is suddenly stopped.
_____________________________________________

Incidentally, the earth orbits the sun at an average of 29.8km/s. Does this mean that a bullet will dribble out of your gun and land harmlessly on the ground depending on which direction you are facing relative to earths orbit? http://forums.ubi.com/images/smilies/88.gif </div></BLOCKQUOTE>
_____________________________________________
No...the bullet then has rotational acceleration
_____________________________________________ </div></BLOCKQUOTE>

http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif
Oh great Flying Spaghetti Monster, give me strength...

Davinci..
03-02-2006, 08:26 PM
Originally posted by KrashanTopolova:
______________________________________________
the sidecar would move on the conveyor because it is remotely connected to the motorcycle which has (and only it has) the moment of force to move the sidecar by the agency of power directed against a non-moving surface (the normal ground off the conveyor belt)...
______________________________________________

how is the motorcycle directing its power to the ground to move, any different then an aircraft directing its power via a prop pushing agains the air??

Z4K
03-02-2006, 11:34 PM
Originally posted by BillPosters:

the *aircraft* would move on the conveyor because it is remotely connected to the *propeller* which has (and only it has) the moment of force to move the *aircraft* by the agency of power directed against a non-moving surface (the normal *air* off the conveyor belt)...

<span class="ev_code_YELLOW">BEST POST EVER
</span>

Burnzoire1
03-02-2006, 11:48 PM
Ladies and gentlemen we have a winner.

Love the sidecar explanation, completely flawless.

Z4K
03-03-2006, 12:05 AM
KrashanTopolova:

You're right about the bullet dribbling out of the end of the gun, motionless (relative to the earth) and falling to the aircraft floor.

Say the tail gunner's in an A380 and 70metres ahead of him is the pilot. The bullet leaves the pilot's gun at 300 ms^-1 relative to the pilot (about the max cruising speed of the A380) and the plane's flying in the other direction at 300ms^-1 relative to the Earth. So the bullet's true velocity (in the direction the plane is flying and measured with reference to the Earth) is 0ms^-1.

The tail gunner is the pilot's twin brother (rough family). The pilot fires from his eye level, which is 1.8m from the aircraft floor, perfectly horizontally.

The bullet accelerates downwards at 9.8ms^-2 due to gravity. It hits the floor, 1.8m below:

S = u * t + 0.5 * a * t^2

S (displacement downwards) = 1.8m
u (Initial downward velocity) = 0 ms^-1
a (acceleration downwards) = g = 9.8ms^-2
t (time) = unknown
<pre class="ip-ubbcode-code-pre">
1.8 = 0 + 0.5 * 9.8 * t^2
t = (1.8/(0.5 * 9.8))^0.5
= (1.8/4.9)^0.5
~ (0.36735)^0.5
~ 0.60609 sec</pre>

It will take about 0.61 seconds to hit the floor.

After 0.60609 seconds, the aircraft and its occupants have moved

<pre class="ip-ubbcode-code-pre">0.60609 * 300 ~= 181m</pre>

Which means that the bullet hadn't hit the floor by the time the tail gunner reached it

<pre class="ip-ubbcode-code-pre">70/300 ~= 0.23333 sec</pre>

after it was fired. The bullet would have dropped

<pre class="ip-ubbcode-code-pre">S = u * t + 0.5 * a * t^2
S = 0 + 0.5 * 9.8 * 0.23333^2
= 0.5 * 9.8 * 0.054444
= 4.9 * 0.054444
~ 0.2668m</pre>

about 27cm. Kind of near the middle of the tail gunner's chest. He ran into it at 300ms^-1 (1080kmh, 583knots, whatever). Sufficiently fast to be bad.

Without horizontal velocity? Absolutely! (relative to the arbitrarily chosen reference point of the Earth. Much better to choose the plane and its occupants, considering they're the people we're interested in. If not the plane, why not Pluto? Or the central black hole of the Andromeda galaxy? The numbers are different, but the tail gunner's still splattered all over the back of the A380 - and don't anyone tell me he's behind the rear pressure bulkhead)

Harmless? No! The tailgunner's dead.

Z4K
03-03-2006, 12:17 AM
Hey Krashan, I'll give you a dollar (Australian, of course) if you can tell me why the puzzle doesn't work because the plane won't move if:

<span class="ev_code_YELLOW">a)</span> Every time you mention "velocity", "speed", or in any way talk about the motion of anything, you include what that velocity/speed/etc is measured against. eg "the plane moves forwards relative to the belt at velocity dx", AND;

<span class="ev_code_YELLOW">b)</span> Only use one reference (otherwise, some velocities/speeds/etc could be measured relative to a particular neutrino that was just blasted out of the sun, and others against the Earth. And that would be ridiculous), AND;

<span class="ev_code_YELLOW">c)</span> Manage not to violate the conditions of the puzzle (or contratict yourself mid-explanation).


I'll post you the dollar. Cash, or money order?

BillPosters
03-03-2006, 02:20 AM
Originally posted by Z4K:
...lots of physics stuff...

Geez, that was almost like one of Krashan's posts except that it was witty, coherent and logically correct. http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

DaimonSyrius
03-03-2006, 03:24 AM
Originally posted by BillPosters:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by KrashanTopolova:
the sidecar would move on the conveyor because it is remotely connected to the motorcycle which has (and only it has) the moment of force to move the sidecar by the agency of power directed against a non-moving surface (the normal ground off the conveyor belt)...

the *aircraft* would move on the conveyor because it is remotely connected to the *propeller* which has (and only it has) the moment of force to move the *aircraft* by the agency of power directed against a non-moving surface (the normal *air* off the conveyor belt)... </div></BLOCKQUOTE>

http://forums.ubi.com/images/smilies/25.gif Billposters http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Now wait to read how KrashanTopolova will compose some nonsense about the viscosity momentum of free-wheeling air molecules being dragged by the conveyor's accelerating surface vector so that the groundspeed of air obviously cannot provide lift to the airspeed of ground...
http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

*munching popcorn*

Cheers,
S.

Jatro13th
03-03-2006, 08:32 AM
1. According to krashan the plane wont move relative to the earth and air (since the two we consider them to be static to each other).
2. At the same time he is saying that the belt will move.

So, the conclusion is that the belt is moving relative to the ground, whereas the plane is not.

Now I want to ask, how the bloody hell is that possible? We know for a fact that the belt is regulated to match the aircrafts speed but in the opposite direction. And that is relative to the ground of course!

If we go according to the logic of Krashan (if you can call that logic of course) the airplane wont budge (relative to the ground) and so should the belt (although Krashan says otherwise)! There are some pixies in the wheels that prevent them from moving!!


Contradictions...
Contradictions...
Contradictions...
Contradictions...

Hehe, this is getting better all the time!


"Double Thought is the ability to know that something is wrong, but at the same time being convinced that this is the greatest truth!"
George Orwell, 1984

"War is Peace, Freedom is Slavery, and the bloody Plane won't take off"

DaimonSyrius
03-03-2006, 08:36 AM
Originally posted by Jatro13th:
1. According to krashan .../...
Hey, I thought you were quitting conveyor belts !
Hard to give up?

Originally posted by Jatro13th on p.8:
couldn't resist myself in the end... I promise this is my last post in the thread:
http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

Cheers,
S.

Wild.Bill.Kelso
03-03-2006, 08:49 AM
Can't believe this topic has 10 pages! http://forums.ubi.com/images/smilies/blink.gif Congratulations! http://smilies.vidahost.com/otn/party/party.gif

Jatro13th
03-03-2006, 11:54 AM
Daimon wrote:
"Hey, I thought you were quitting conveyor belts !
Hard to give up?"

I'm too prone to my bad habits...

Damn, this is becoming an addiction!!

Need... to get.... c-conveyor... b-b-belt-t......

http://forums.ubi.com/images/smilies/35.gif

Burnzoire1
03-03-2006, 03:48 PM
You really don't need to say anything more since that sidecar post. By posting more he'll just reply to those posts instead of the one that he really can't answer. He's failed to answer anything that solidly proves he's wrong, instead he'll choose something he can twist with his disney physics.

KrashanTopolova
03-03-2006, 03:58 PM
Originally posted by Davinci..:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by KrashanTopolova:
______________________________________________
the sidecar would move on the conveyor because it is remotely connected to the motorcycle which has (and only it has) the moment of force to move the sidecar by the agency of power directed against a non-moving surface (the normal ground off the conveyor belt)...
______________________________________________

how is the motorcycle directing its power to the ground to move, any different then an aircraft directing its power via a prop pushing agains the air?? </div></BLOCKQUOTE>
____________________________________________
There are basically two types of propellor force depending on where the propellor is situated on the airframe...a propellor that 'pushes' (as you say) is generally situated behind the wing...a propellor situated in front of the wing is a 'Tractor'...it screws through the air.
____________________________________________

elphifou
03-03-2006, 04:02 PM
[QUOTE]Originally posted by KrashanTopolova:
There are basically two types of propellor force depending on where the propellor is situated on the airframe...a propellor that 'pushes' (as you say) is generally situated behind the wing...a propellor situated in front of the wing is a 'Tractor'...it screws through the air.
QUOTE]

... and ? http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

elphifou
03-03-2006, 04:03 PM
... so ?

elphifou
03-03-2006, 04:04 PM
... your conclusion is ?

KrashanTopolova
03-03-2006, 04:08 PM
Originally posted by Z4K:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BillPosters:

the *aircraft* would move on the conveyor because it is remotely connected to the *propeller* which has (and only it has) the moment of force to move the *aircraft* by the agency of power directed against a non-moving surface (the normal *air* off the conveyor belt)...

<span class="ev_code_YELLOW">BEST POST EVER
</span>
</div></BLOCKQUOTE>

______________________________________________
No..in fact this is the correct answer:
If the CBF's can't prove that any movement forward relative to the fixed points in space of the wheel circumference while on the conveyor is NOT instantly dissipated or negated by a reverse displacement (spatially relative) then they fail to prove (or are not entitled to suggest the 'puzzle') that there is acceleration forward on the conveyor belt.

They can only do what they have consistently done...make a claim (in the guise of a 'puzzle')

They do not hit the nail on the head...they hit their head on the nail.

In the end it must be realised that parity of displacement MUST BE TRUE if both forward and reverse velocities are the same (as stated as the primary condition that the conveyor keep up with their so-called 'speed' of the aircraft.

Hence if no acceleration...then no lift.

Having got a feel for this cult-like idea (the 'puzzle'), the CBF's seem to be of those that are mesmerised by any machine with bells and whistles...anything with flashing lights...and any book must for them have pictures also...
____________________________________________

BaldieJr
03-03-2006, 04:12 PM
I just tried this test and the airplane did not fly. I did it at walmart with one of those wind-up balsa planes on check-out line 14's belt.

KrashanTopolova
03-03-2006, 04:18 PM
Originally posted by Davinci..:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by KrashanTopolova:
______________________________________________
the sidecar would move on the conveyor because it is remotely connected to the motorcycle which has (and only it has) the moment of force to move the sidecar by the agency of power directed against a non-moving surface (the normal ground off the conveyor belt)...
______________________________________________

how is the motorcycle directing its power to the ground to move, any different then an aircraft directing its power via a prop pushing agains the air?? </div></BLOCKQUOTE>
_______________________________________________
the traction of the wheels on the ground is enhanced by the ground being stationary relative to the fixed points in space. Thus the momentum forward in that case is acceleration relative to the fixed points in space. In fact maximum design efficiency.

In contrast, the traction of the wheels on the conveyor is the same (from the normal force and gravitational force (weight))...but the fact that it is slipping relative to the fixed points in space indicates that if any velocity arises it is from such an inefficient source that it is more likely that such a velocity will become terminal relative to the fixed points in space. Hence there is no basis for the suggestion made by the CBF's that the length of conveyor required is about equal to a normal fixed runway...
______________________________________________

KrashanTopolova
03-03-2006, 04:23 PM
Originally posted by BaldieJr:
I just tried this test and the airplane did not fly. I did it at walmart with one of those wind-up balsa planes on check-out line 14's belt.

____________________________________________
That's what we need...someone with balsa...!

However, maybe the balsa plane should have flown since the power to weight ratio could mean that that sort of thrust should overcome any opposite force.

Did you notice the look on the checkout operator's face by any chance...?

If asked she might have known the answer to this 'puzzle' from the number of items that fall over or slide off on her conveyor belt...
_____________________________________________

Z4K
03-04-2006, 09:14 AM
Originally posted by KrashanTopolova:
In the end it must be realised that parity of displacement MUST BE TRUE if both forward and reverse velocities are the same (as stated as the primary condition that the conveyor keep up with their so-called 'speed' of the aircraft...

"Parity of displacement", as you put it, IS TRUE in the "CBF" view, and only in the CBF view. If the conveyor has moved backwards distance dx (rte*), then the plane MUST HAVE (according to your capitalised assertion above) moved dx forward (rte).

This shows that acceleration (rte) of the aircraft is not zero. Which shows that the plane, ******ed by the conveyor or not, can move (rte) at an arbitrary rate. Given that, it just remains to choose a plane that has enough power to overcome the ******ing forces on it sufficient to reach take-off velocity (rte) - just like one does with a plane on a normal runway.

There's no fundamental difference - at least that's what I get from "...that parity of displacement MUST BE TRUE if both forward and reverse velocities are the same..." which, incidentally, is the most rational thing you've written in this thread.



* rte: relative to the Earth

Also: the tailgunner's still dead, the sidecar still moves, and your dollar's sitting here waiting.

Xiolablu3
03-04-2006, 04:34 PM
Lol are you STILL going on about this??

Krash - You say there is no lift, so the plane will not fly.

BUT there IS lift and forward movement, the plane moves forward by means of its propellor pulling it thru the air, just like any plane does. If it was a jet plane, the Jet would push it forwards.

The conveyer belt can spin as fast as it likes and the wheels can do what the hell they want, the propellor is still going to pull the plane forward, or the jet is going to push it forward, it will gain speed as normal and take off on a conveyor as long as a normal runway.

The wheels have nothing to do with a planes movement, its the propellor or Jet engine using the air to drive it forwards.

That is probably the simpliest explanation you are going to get, if you cant see it from this then God help you mate http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Burnzoire1
03-04-2006, 09:08 PM
he seems to think that power from the ground (the sidecar) and power from the air (plane) is different.

How so? I fthat were the case we wouldn't have aircraft, so to speak. Whatever the differences they have no effect on this scenario as the conveyor belt doesn't affect the air in which the propellor/jet operates. Nothing changes buddy, that's why the sidecar doesn't affect the motorcycle and that's why the aircraft's wheels won't affect takeoff.

It makes sense to everyone here, but if you want to keep hiding behind your equations then be my guest. You won't convince anyone with half a brain. Explain it it plain english then you may get somewhere. And yes, even complex situations can be explained in english - infact if you can't explain it simply it usually means you don't understand it yourself.

Jatro13th
03-05-2006, 03:48 AM
It is known that a classic full length mucoperiosteal incision which incorporates the papilla leads to recession of the gingivae and in most cases of crown restored teeth, to the exposure of the restoration margins. This can be the reason (as far as aesthetics are concerned) for the replacement of said restoration for reasons other than failure.
On the other hand, the Papilla Sparing incisions (such as Papilla Bas Incision or the older Luebke-Oschenbein Incision) are very promising in terms of gingival recession and preservation.
The evidence available, though, is of little quantity and credibility.
Experience has shown the aforementioned statements to be true, but, it is not enough to change the way incisions are taught in Dental Schools.
It is therefore imperative to carry out more studies in the fashion of Randomised Control Trials to prove what experience has shown.
The protocol for this study will be soon published.

That is why I am convinced that the plane will take off!!!!
http://forums.ubi.com/images/smilies/35.gif http://forums.ubi.com/images/smilies/35.gif

NonWonderDog
03-05-2006, 07:54 AM
There you go, now you're speaking Krashan's language. http://forums.ubi.com/images/smilies/clap.gif

DaimonSyrius
03-05-2006, 08:28 AM
...with the difference that what Jatro is saying makes sense, at least in periodontal surgery, or in the general subject of dentistry http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

Whereas any appearance of sensible content in KrashanTopolova's writings is only, at most, an ephemeral illusion http://forums.ubi.com/images/smilies/winky.gif

Cheers,
S.

Stafroty
03-05-2006, 08:51 AM
lol@Ubiforummembers http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Xiolablu3
03-05-2006, 09:46 AM
Originally posted by Stafroty:
lol@Ubiforummembers http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Ahhh I see you find yourself funny??? http://forums.ubi.com/images/smilies/35.gif

I think this must be a wind up from someone trying to reel people in, but failing miserabley.

Does ANYONE actually agree with Krash?
Noone can surely misunderstand the problem that much?

Jatro13th
03-05-2006, 10:21 AM
Where Xiolablu3 left his sentence:

No one can surely misunderstand the problem that much...

And I complement:

...not even Krash!

KrashanTopolova
03-05-2006, 03:28 PM
Originally posted by KrashanTopolova:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BaldieJr:
I just tried this test and the airplane did not fly. I did it at walmart with one of those wind-up balsa planes on check-out line 14's belt.

____________________________________________
That's what we need...someone with balsa...!

However, maybe the balsa plane should have flown since the power to weight ratio could mean that that sort of thrust should overcome any opposite force.

Did you notice the look on the checkout operator's face by any chance...?

If asked she might have known the answer to this 'puzzle' from the number of items that fall over or slide off on her conveyor belt...
_____________________________________________ </div></BLOCKQUOTE>

I'm sorry BaldieJr but I must use your post to reply to a moronic post just below yours. This is because the Mods don't believe in granting freedom of speech and have lock the thread as from your last post;

So: in reply to Z4K or whatever...you took my solution out of context and substituted your own reality like some sort of Mythbuster...this taking out of context and substituting home-grown 'facts' is displayed consistently as a tactic in this thread by the CBF's.

In fact what is stated as a condition of the 'puzzle' is that the aircraft moves first to which movement the conveyor responds (I hope you can see how you twisted that around to try and defeat me)...

Also: you only show a calculus operation but do not relate it to any equation...

The only equations possible (as I've suggested all along and as you confimed in your post below is that x=0 and y=0)...no meaningful calculus possible there buddy...

Burnzoire1
03-05-2006, 04:37 PM
So prove to me again why the motorcycle sidecar is different to the aircraft?

Unless you live on a different dimension your 'explanations' haven't been very convincing.

KrashanTopolova
03-05-2006, 06:30 PM
Originally posted by Burnzoire:
So prove to me again why the motorcycle sidecar is different to the aircraft?

Unless you live on a different dimension your 'explanations' haven't been very convincing.
______________________________________________
The motorcycle car is the equivalent body to the fusealge of the aircraft. The side car however, is connected remotely to a source having maximum traction and moment of force...Through Wheels on a non-moving surface. This naturally leads to displacement of both connected bodies relative to the fixed points in space.

Now:
Imagine the aircraft motor taken off the fuselage and placed where the motorcycle is (on a metal arm suspended off the ground outside the conveyor belt (say). In that instance there is no maximum efficiency of grip solid to solid upon which force is derived and delivered to the sidecar/aircraft fuselage...there is only a mechanism to 'swim' or 'screw' its way through a gas hence trying to take along anything remotely attached to it (fuselage).

That is the first point of difference...you can't compare oranges and lemons even though they are related.

The second point of difference is that the efficiency of transmitting force is reduced on a reverse moving surface...whether to zero depends on the (realistic)thrust available...and that is the crux of the 'puzzle'.

From there one should see that things like displacement, speed, velocity, acceleration etc. are all dependant on rates of change which are dependant on the power to weight ratio (thrust v drag). If the surfaces of force receiving/transmission were still this is easily measured...but of course they are not.

The third difference is frame of perception...CBF's do not admit that there are no relative velocities possible in this 'puzzle'. It is not possible because the aircraft moves first and its displacement relative to the fixed points of space is either instantly negated by the conveyor or thae aircraft makes gains in displacement until thrust no longer keeps up with the detraction of velocity by the reverse momentum of the conveyor and hence a terminal velocity is reached (no more acceleration).
______________________________________________

p-11.cAce
03-05-2006, 06:41 PM
its displacement relative to the fixed points of space is either instantly negated by the conveyor or thae aircraft makes gains in displacement until thrust no longer keeps up with the detraction of velocity by the reverse momentum of the conveyor and hence a terminal velocity is reached
How? This is the crux of your argument Krash- how is the displacment of the aircraft negated by the conveyor belt? The force exerted by the conveyor belt is exerted upon free turning wheels - and that force spins the wheels but with the exception of a marginal increase in bearing drag it would in no way impede the forward motion of the aircraft.

Burnzoire1
03-05-2006, 07:27 PM
"connected remotely"
It's connected or it's not. We're talking a solid rigid connection. Motorcycle sidecar & aircraft are no different here.

"non-moving surface"
The air with which the engine operates does not move with the conveyor belt, thus it operates no differently. The power is therefore no different to being on a normal runway.

"maximum efficiency"
See above. Both aircraft and motorbike still operate with maximum efficiency. Your converyor belt has no effect on the air, so that just leaves us with the wheels... tell me what is different about the sidecar's wheels to the aircraft's wheels then? To make things even lets throw some extra weight in the sidecar, the results are much the same as running on solid ground, with negligable friction.

"reduced on a reverse moving surface"
The conveyor belt is acting on the wheels, which in turn do nothing but spin on an axis. I can't explain this any simpler, nor can the masses of people on this forum. The belt certainly does not affect the engine's airflow, so this reverse moving surface isn't reducing a thing.

"either instantly negated by the conveyor or the aircraft makes gains in displacement until thrust no longer keeps up with the detraction of velocity by the reverse momentum of the conveyor and hence a terminal velocity is reached (no more acceleration)."
Why would the thrust of an aircraft no longer keep up with the reverse momentum of the conveyor belt? Your statement does nothing but reiterate your obsurd claim. Terminal velocity? There is nothing to stop the aircraft from accellerating away, nothing at all.
The aircraft is not going up-hill, it's not getting pushed or pulled by anything. Your Thrust vs Drag argument really doesn't hold up here, we're on wheels with negligable friction no matter how fast they spin. This spinning motion will not push the aircraft backwards, and the engine will continue to perform as per normal and propell the aircraft forward. You can't see the forest through the trees.

Akronnick
03-06-2006, 12:30 AM
Originally posted by KrashanTopolova:

That is the first point of difference...you can't compare oranges and lemons even though they are related.


My orange is sweeter than my lemon.

They are both yellow.

I bought both of them at Kroger.

They were both grown in Florida.

Wow, I guess I can compare oranges an lemons.


This guy reminds me of that Japanese guy who refused to believe WWII was over until the seventies.

Keep fightin' the good fight Krashan, Galileo will be proud of you.

No, wait, Galileo was right, the Earth ISN'T the center of the Universe.

Makes me wonder what other things people who don't understand science yet argue about as if their life depends on it might be wrong about.

Akronnick
03-06-2006, 12:33 AM
Dagnabbit I just bumped this ridiculous topic to the top again

</ EpIII Darth Vader Mode ON>

Noooooooooooooooooooo!!!!!!!!!!!!

</Darth Vader Mode OFF>

rnzoli
03-06-2006, 02:31 AM
Akronnick, we'll shoot you for this http://forums.ubi.com/images/smilies/51.gif virtually, of course http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

KrashanTopolova
03-06-2006, 03:23 PM
Originally posted by p-11.cAce:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> its displacement relative to the fixed points of space is either instantly negated by the conveyor or thae aircraft makes gains in displacement until thrust no longer keeps up with the detraction of velocity by the reverse momentum of the conveyor and hence a terminal velocity is reached
How? This is the crux of your argument Krash- how is the displacment of the aircraft negated by the conveyor belt? The force exerted by the conveyor belt is exerted upon free turning wheels - and that force spins the wheels but with the exception of a marginal increase in bearing drag it would in no way impede the forward motion of the aircraft. </div></BLOCKQUOTE>
___________________________________________
I think we have a problem with frame of reference here:
The conveyor is independant of most of the forces except the normal force (the force exerted by the conveyor on the aircraft wheels) and the gravity force (weight of the aircraft)...it is these that are related to the fixed points in space...and any ******ation of velocity relative to the fixed points in space are referenced by these forces.

the key is to determine if there is any forward momentum of the aircraft relative to the fixed points in space outside the conveyor.

You were cool on this frame of reference some posts ago but seem to be flip flopping now...one can't sit in the driver's seat and notice only the conveyor belt running, since then it would appear as if one was rolling down the runway...that is the effect of free-running wheels in that particular frame of reference.
_______________________________________________

Akronnick
03-06-2006, 03:40 PM
Originally posted by KrashanTopolova:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by p-11.cAce:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> its displacement relative to the fixed points of space is either instantly negated by the conveyor or thae aircraft makes gains in displacement until thrust no longer keeps up with the detraction of velocity by the reverse momentum of the conveyor and hence a terminal velocity is reached
How? This is the crux of your argument Krash- how is the displacment of the aircraft negated by the conveyor belt? The force exerted by the conveyor belt is exerted upon free turning wheels - and that force spins the wheels but with the exception of a marginal increase in bearing drag it would in no way impede the forward motion of the aircraft. </div></BLOCKQUOTE>
___________________________________________
I think we have a problem with frame of reference here:
The conveyor is independant of most of the forces except the normal force (the force exerted by the conveyor on the aircraft wheels) and the gravity force (weight of the aircraft)...it is these that are related to the fixed points in space...and any ******ation of velocity relative to the fixed points in space are referenced by these forces.

the key is to determine if there is any forward momentum of the aircraft relative to the fixed points in space outside the conveyor.

You were cool on this frame of reference some posts ago but seem to be flip flopping now...one can't sit in the driver's seat and notice only the conveyor belt running, since then it would appear as if one was rolling down the runway...that is the effect of free-running wheels in that particular frame of reference.

Krashan, You said that the only forces between the the plane and the conveyor are the Normal force and gravity. Answer this question:
What direction do each of these forces act in?
_______________________________________________ </div></BLOCKQUOTE>

KrashanTopolova
03-06-2006, 03:42 PM
Originally posted by Burnzoire:
"connected remotely"
It's connected or it's not. We're talking a solid rigid connection. Motorcycle sidecar & aircraft are no different here.

"non-moving surface"
The air with which the engine operates does not move with the conveyor belt, thus it operates no differently. The power is therefore no different to being on a normal runway.
_______________________________________________
the proportional power is therefore no different proportionally to being on a normal runway
_______________________________________________

"maximum efficiency"
See above. Both aircraft and motorbike still operate with maximum efficiency.
______________________________________________
not in relation to the fixed points in space
______________________________________________
Your converyor belt has no effect on the air, so that just leaves us with the wheels... tell me what is different about the sidecar's wheels to the aircraft's wheels then? To make things even lets throw some extra weight in the sidecar, the results are much the same as running on solid ground, with negligable friction.
_______________________________________________
The conveyor of course has an effect on the air in which it moves...however, throw in as much 'weight' as you like...the motorcycle sidecar's wheels are being moved by an external agent off the conveyor...in contrast, the aircraft's wheels are being moved by the conveyor and the thrust (if, as is stated, the conveyor is instantly calibrated to match the aircraft's so-called 'speed'.
_______________________________________________


"reduced on a reverse moving surface"
The conveyor belt is acting on the wheels,
__________________________________________
confirmation of the above...
__________________________________________
which in turn do nothing but spin on an axis.
______________________________________________
which in turn do not do nothing... they are a translational agent of power which may, if conditions exist express that power in any number of dimensional units...speed, velocity, acceleration...work...energy...etc.
______________________________________________
I can't explain this any simpler, nor can the masses of people on this forum. The belt certainly does not affect the engine's airflow, so this reverse moving surface isn't reducing a thing.
________________________________________________
of course the conveyor can affect any airflow...
it is not remote from its surrounding air mass, even though the CBF's maintain this to support the CBF theory...



Reverse momentum reduces forward momentum relative to the fixed points in space...
________________________________________________

"either instantly negated by the conveyor or the aircraft makes gains in displacement until thrust no longer keeps up with the detraction of velocity by the reverse momentum of the conveyor and hence a terminal velocity is reached (no more acceleration)."
Why would the thrust of an aircraft no longer keep up with the reverse momentum of the conveyor belt? Your statement does nothing but reiterate your obsurd claim. Terminal velocity? There is nothing to stop the aircraft from accellerating away, nothing at all.
The aircraft is not going up-hill, it's not getting pushed or pulled by anything. Your Thrust vs Drag argument really doesn't hold up here, we're on wheels with negligable friction no matter how fast they spin. This spinning motion will not push the aircraft backwards, and the engine will continue to perform as per normal and propell the aircraft forward. You can't see the forest through the trees.
_______________________________________________aac celeration is dependent on the rate of change of velocity...(which latter is in fact the definition of acceleration).

Thrust may indeed not keep up with the reverse forces of momentum because of the forces acting on the aircraft not necessarily because of forces on, from or about the conveyor belt
_______________________________________________


'....There is not one shred of evidence to support the assertion that life is serious...' (Anonymous)
_______________________________________________

KrashanTopolova
03-06-2006, 03:46 PM
Originally posted by Akronnick:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by KrashanTopolova:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by p-11.cAce:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> its displacement relative to the fixed points of space is either instantly negated by the conveyor or thae aircraft makes gains in displacement until thrust no longer keeps up with the detraction of velocity by the reverse momentum of the conveyor and hence a terminal velocity is reached
How? This is the crux of your argument Krash- how is the displacment of the aircraft negated by the conveyor belt? The force exerted by the conveyor belt is exerted upon free turning wheels - and that force spins the wheels but with the exception of a marginal increase in bearing drag it would in no way impede the forward motion of the aircraft. </div></BLOCKQUOTE>
___________________________________________
I think we have a problem with frame of reference here:
The conveyor is independant of most of the forces except the normal force (the force exerted by the conveyor on the aircraft wheels) and the gravity force (weight of the aircraft)...it is these that are related to the fixed points in space...and any ******ation of velocity relative to the fixed points in space are referenced by these forces.

the key is to determine if there is any forward momentum of the aircraft relative to the fixed points in space outside the conveyor.

You were cool on this frame of reference some posts ago but seem to be flip flopping now...one can't sit in the driver's seat and notice only the conveyor belt running, since then it would appear as if one was rolling down the runway...that is the effect of free-running wheels in that particular frame of reference.

Krashan, You said that the only forces between the the plane and the conveyor are the Normal force and gravity. Answer this question:
What direction do each of these forces act in?
_______________________________________________ </div></BLOCKQUOTE> </div></BLOCKQUOTE>
_______________________________________________
Normal force acts vertically upward, Weight acts vertically downward...this maintains true unless another force vector is introduced that is at an angle different to the those two forces...
_______________________________________________

Burnzoire1
03-06-2006, 03:48 PM
Nothing you say makes any sense. Goodbye.

KrashanTopolova
03-06-2006, 04:09 PM
Originally posted by Burnzoire:
Nothing you say makes any sense. Goodbye.

i'm sorry...perhaps I expressed that badly.

obviously the weight and normal forces would act vertically all the time (even though if you stand on the surface of a sphere those forces would act in different directions at different points on the surface of the sphere...but that is practically irrelevant to this 'puzzle')

I was intuitively trying to get across the idea of a Resultant (net effect of the sum of all forces)on the aircraft's momentum in the 'puzzle'.

In the end I'm only questioning people's visualisation of both the 'puzzle' and it's 'solution(s)'...

Stay Cool...

NonWonderDog
03-06-2006, 08:52 PM
Forces normal to the direction of travel are completely irrelevant to this discussion.

The only thing weight (as opposed to mass) affects in this situation is bearing friction and tire slip angles. Neither effect has any relevance in this situation.

People aren't ignoring vertical forces because of "poor visualization," they're ignoring them because they are of no importance.


In fact, the riddle isn't even a physics question. It explicity states that the aircraft moves forward! The riddle is, however, very good at convincing those who don't know any better that it is a physics question.

KrashanTopolova
03-06-2006, 09:55 PM
Originally posted by NonWonderDog:
Forces normal to the direction of travel are completely irrelevant to this discussion.
_______________________________________________
Oh Yeah...?
without inertia (under weight and the normal force) there is no travel buddy...it's inertia that gradually reduces under thrust making the bicycle easier to pedal...or the aircraft to accelerate...yes/no?
_______________________________________________


The only thing weight (as opposed to mass) affects in this situation is bearing friction and tire slip angles. Neither effect has any relevance in this situation.
____________________________________________
ho, hum...

get your physics right...weight can vary with position on the surface of the earth...mass is constant (under Newton at least)...mass is related to inertia and to travel etc.
Weight on the other hand is related to the amount of mass you can lose if you stop eating candy at the computer...or stand on the moon without giving up your candy...
____________________________________________


People aren't ignoring vertical forces because of "poor visualization," they're ignoring them because they are of no importance.
______________________________________________
i don't think they are ignoring anything important ...just trying to get to grips with understanding a poorly set out 'puzzle'
______________________________________________


In fact, the riddle isn't even a physics question. It explicity states that the aircraft moves forward! The riddle is, however, very good at convincing those who don't know any better that it is a physics question.
____________________________________________
The riddle implies a physics solution for anything moving forward...
___________________________________________

KrashanTopolova
03-07-2006, 05:27 PM
Wow...I tuned into the forum today and no-one responded to my last post...


I must have won...!

I'm not surprised because inertia is the crux of the problem...something I pointed to when I first mentioned Newton's first Law of motion...


But then I digressed slightly (but not without relevance) into Newton's Third because I wanted to achieve 15 pages of thread...

Inertia...that must be it...!
An aircraft has a big chore already overcoming inertia on a non-moving surface to achieve velocity and then acceleration...
of course!...inertia...!

The reverse movement of the conveyor belt complements inertia...(why didn't I think of that before I first thought of it...?)

Therefore...the aircraft will struggle to achieve a velocity vector relative to the fixed points in space and even if it does achieve acceleration from compounding velocity on the conveyor the inertia in this 'puzzle' is too great to sustain acceleration....hence teminal velocity if the aircraft is not already sitting back where it was first positioned...

Now all I need is a physicist to tell me if I am right...

_____________________________________________
'...play the last post burglar because due to dumbfoundedness I think my velocity has become terminal and I won't make it to 15...'
______________________________________________

elphifou
03-07-2006, 05:44 PM
Nuh uh... I sense this thread is gonna make it through page 13.

13 ?.. "13" !! http://forums.ubi.com/images/smilies/blink.gif
Wait... no, I don't wanna see this ! http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

See you guys at page 14 then http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif http://forums.ubi.com/images/smilies/sleepzzz.gif

Xiolablu3
03-07-2006, 05:46 PM
Originally posted by KrashanTopolova:
Wow...I tuned into the forum today and no-one responded to my last post...


I must have won...!


http://forums.ubi.com/images/smilies/34.gif You just keep believing that buddy.

Cajun76
03-07-2006, 08:43 PM
Originally posted by KrashanTopolova:
Wow...I tuned into the forum today and no-one responded to my last post...


I must have won...!

I'm not surprised because inertia is the crux of the problem...something I pointed to when I first mentioned Newton's first Law of motion...


But then I digressed slightly (but not without relevance) into Newton's Third because I wanted to achieve 15 pages of thread...

Inertia...that must be it...!
An aircraft has a big chore already overcoming inertia on a non-moving surface to achieve velocity and then acceleration...
of course!...inertia...!

The reverse movement of the conveyor belt complements inertia...(why didn't I think of that before I first thought of it...?)

Therefore...the aircraft will struggle to achieve a velocity vector relative to the fixed points in space and even if it does achieve acceleration from compounding velocity on the conveyor the inertia in this 'puzzle' is too great to sustain acceleration....hence teminal velocity if the aircraft is not already sitting back where it was first positioned...

Now all I need is a physicist to tell me if I am right...

_____________________________________________
'...play the last post burglar because due to dumbfoundedness I think my velocity has become terminal and I won't make it to 15...'
______________________________________________

What properties does the conveyer belt impart to the aircraft to change the planes' fundemental inertia?

None.

So your argument dosen't hold water, at all.

An a/c's inertia and thrust remain constant throughout a wide range of conditions, whether on a runway, on ice, an aircraft carrier, or on a conveyer belt.

If the conveyer were to start rapidly spinning either forward or backward, the a/c might well stay in one spot. Think about the way it works when someone snatches a tablecloth off a fully laden table.

But when you add the thrust of an engine to the equation, that's the variable that trancends the minor friction the wheels generate against the conveyer. If it were inertia like you describe, no plane nor vehicle could ever move.


Try this one:

Ever seen Knight Rider? When the car gets on and off the semi truck while it's moving? If Kit is travling at 62mph as it approaches the semi going 60, the car is not going to shoot forward to 122mph when it gets on the ramp. Take it out of gear or let off the gas, and viola!, it's on the truck.

Same for getting off. The car dosen't just come to a stop when it leaves the truck, or even keep reversing at 2mph. It is going nearly the same speed as the semi, even though an instant before it was traveling -2mph, relative to the semi. The car didn't accelerate from -2 to 58mph instantly, but the free spinning wheels did. (I would assume that the car is put in neutral just before coming off the ramp, and then put in gear with some throttle applied)


<span class="ev_code_YELLOW">Even so, thrust overcomes inertia and drag during takeoff all the time, the conveyer has no effect, since it's only conection to the a/c is through wheels that spin freely.</span>

rnzoli
03-08-2006, 02:10 AM
Originally posted by KrashanTopolova:
Now all I need is a physicist to tell me if I am right...
http://forums.ubi.com/images/smilies/10.gif Ask a <span class="ev_code_RED">physician</span> instead http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

p-11.cAce
03-08-2006, 05:31 AM
Ever seen Knight Rider? When the car gets on and off the semi truck while it's moving? If Kit is travling at 62mph as it approaches the semi going 60, the car is not going to shoot forward to 122mph when it gets on the ramp. Take it out of gear or let off the gas, and viola!, it's on the truck.

Same for getting off. The car dosen't just come to a stop when it leaves the truck, or even keep reversing at 2mph. It is going nearly the same speed as the semi, even though an instant before it was traveling -2mph, relative to the semi. The car didn't accelerate from -2 to 58mph instantly, but the free spinning wheels did. (I would assume that the car is put in neutral just before coming off the ramp, and then put in gear with some throttle applied)

The Hoff approves of this post http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif
http://i25.photobucket.com/albums/c99/acmeaviator/knight-rider-interior1.jpg

Tully__
03-08-2006, 07:05 AM
I haven't read the whole thing (and yes, I know it's a fishing expedition)... has anyone pointed out yet that if the movement of the conveyor belt prevents the aircraft from moving, then according to the initial conditions (conveyor speed equal to but opposite direction from the aircraft) the lack of movement in the aicraft will prevent the conveyor from moving. Anyone who successfully proves that the aircraft wont move has also proved that you can stop a conveyor by putting an aircraft on it http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Edit: found the first hint of it on page 9 http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

BaldieJr
03-08-2006, 08:19 AM
oleg must model planes taking off from conveyor belts

Jatro13th
03-08-2006, 09:15 AM
God, Iwas off my drug for a couple of days and now I'm shaking! My old PSU went to meet some friendly garbage and a new one was installed. The PSU is dead, Long Live the PSU!

Anyway, Tully, I think I explained twice to Krash as to why his thoughts cancel each other. The aircraft doesn't move, therefore, the belt doesn't move, therefore the a/c is free to move, therefore the belt starts moving, therefore the plane is stopped by Krash's Super Friction, therefore the plane doesn't move, therefore... (Da Capo Al Fine)...

His way of thinking reminds me an Ancient Greek called Epimenides from the island of Crete who said:

"Cretans (the people from Crete) are always lying."

You can see the eternal loop that occurs in his words. If creatans are lying, then, because he is a Cretan, he is lying too. If he is always lying, then, the words he said are false. If his words are false, then the Creatans don't lie. If the Creatans don't lie, then he is not lying either. If he is not lying, then his words are true. If his words are true, then all the Cretans (including him) lie, etc etc etc...

That's exactly what Krash is implying with his dead-end logic.

DaimonSyrius
03-08-2006, 09:36 AM
Originally posted by Jatro13th:
God, Iwas off my drug for a couple of days and now I'm shaking!
.../...
His way of thinking reminds me an Ancient Greek called Epimenides from the island of Crete who said:
"Cretans (the people from Crete) are always lying."
.../...

I'm glad to see you managed to pick your sanity back off some pocket http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Just a further observation on the way KrashanTopolova's physics would be (if true at all) a continued source of paradox:

We could consider the whole Earth as a huge conveyor belt running Eastwards; Krashan's physics would dictate that aircraft could only takeoff eastwards or maybe flying N or S, but when trying to take off towards the West (270º) the Earth running under the free-wheeling wheels would prevent takeoff! This effect would be maximal on the Equator and null on the Poles. http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

And we could then combine the above with a matching physics set for weather, so adding wind to the picture would make everything the even more paradoxical http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

Cheers,
S.