1. #101
    Originally posted by Whirlin_merlin:
    Er boys you're arguing with each other over frictionless wings in a Raaaid thread, er hello.
    No, we're not. My statement was clearly limited to the shape of the wing. Being wrong about a flat wing producing no lift in level flight, Goya diverted the discussion to friction. Once again, my original statement said NOTHING about friction.

    --Outlaw.
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  2. #102
    Originally posted by OD_:
    I have one question...If a plane is 'flying' on an ideal liquid...isn't it floating? In which case how can it go higher and surely the top of the liquid is as high as it gets...and if it is under the liquid then it must be a submarine!!!
    raaaid didn't say "ideal liquid", he said "ideal fluid." Air is a fluid.


    --Outlaw.
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  3. #103
    You had to spoil it! lol

    Only thing is...on a serious note...it's a what if, but how about what if there was no ideal fluid? (Why you're insisting on calling it that I don't know, could just call it a gas so we'd all know what you're talking about!) Surely the ideal fluid is a vacuum...but then there would be no fluid and no lift...so where would all the free energy go?

    Don't fish swim south for the winter?!?
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  4. #104
    raaaid's Avatar Senior Member
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    You are wrong. The time is not the same
    i disagree take the earth for example it makes half ellipse in half year and the other half in the other half of the year

    both halfs last exactly the same

    an ellipse in fact is half outwards spiral an half inwards from the focus
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  5. #105
    Originally posted by raaaid:
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">You are wrong. The time is not the same
    i disagree... </div></BLOCKQUOTE>

    It doesn't matter if you agree or not. You are still wrong.

    If your equations of motion show differently, then post them. Until then, you are wrong.

    --Outlaw.
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  6. #106
    raaaid's Avatar Senior Member
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    http://csep10.phys.utk.edu/astr161/l...ry/kepler.html

    II. The line joining the planet to the Sun sweeps out equal areas in equal times as the planet travels around the ellipse

    being areas divided by the major axe equal times are equal

    do you think kepler is wrong?

    at least you see my point on tension on the cable being minor in the outwards spiral than in the inwards

    thats easy to understand thinking that for the outwards spiral spool slight friction is enough to shape the spiral
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  7. #107
    Originally posted by raaaid:
    do you think kepler is wrong?
    No, Kepler is right, you are wrong.

    You are incapable of analyzing the system correctly. You cannot derive the equations of motion. You cannot draw the free body diagram. You are wrong.

    Why do you continue to post links to various, sometimes related, websites when all you need to do to convince anyone is show your work? You claim to have spent thousands of hours studying these things yet you show nothing.

    --Outlaw.
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  8. #108
    raaaid's Avatar Senior Member
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    i cant make a free force diagram since for every force you have to draw the reaction

    my point is you can have a big action with a small reaction

    i try to prove it as i see it

    the looping yoyo makes an ellipse, conservation of angular momentum states that equal areas are swept in equal times, being both half areas divided by the longest axe equal times are equal

    whats wrong about this this is classic physics

    my only point of disagreement with classic phisics is that the tension of the string is minor in an outwards spiral than in and inwards one

    this only i can prove it with the thought experiment of a spinning cannonbal where the slight friction of the spool will make the cannonball follow a spiral so tension must be minimal

    i dont have a doubt that even being right i wont get this trough, people believe to much what they study and this is against it and do you think a guy like me would be allowed to change all known creationist physics without counting if it lead to 0 point energy

    talking back on wings if you consider a plane floats due to an increase of density of the fluid due to speed just by going faster you should float more without a need of losing speed on an ideal case
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  9. #109
    raaaid, first prove that a looping yoyo forms an ellipse. And come up with some sort of an idea of how much energy must be input to begin the loop and to maintain the loop.

    Secondly, the terms you have been needing to better describe equal times are perigee and apogee.

    Thirdly, the Kepler law you quotes shows equality in areas not time.
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  10. #110
    DuxCorvan's Avatar Banned
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    Raaaid, it's not Kepler who is wrong. It's you.

    Earth moves faster in its aphelion than in its perihelion. The reasons why areas are the same for the same time, is because the distance to the sun is much longer when the earth is slower, and faster when that distance is shorter. In fact, Earth spends most time of the year in the outer part of the ellipse, and the time it spends near the sun (aphelion) is much shorter.

    You should know that, for the gravity acceleration increases inversely to distance. That's Newton, not Kepler.

    So, are half ellipses equal in the time Earth takes to complete them? Well, if you take the two halves longitudinally (from aphelion to perihelion), yes, they are. But if you compare the side where the Sun is the focus, and the other one, this latter takes much longer.
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