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Dyanmics question

  1. Jul 27, 2005 #1
    why does drag produce lift?
  2. jcsd
  3. Jul 27, 2005 #2


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  4. Jul 27, 2005 #3

    Actually, that thread is filled with a lot of consfusing ideas, some of which
    are actually correct.

    Lift is the force on a wing (hopefully upward) which is created by the
    fact that the pressure above the wing is lower than the pressure below it.

    Drag is a force that wants to push the wing in the direction that the air
    is flowing.

    The engine must supply power to overcome the drag or the plane will
    slow down. Drag is the reason why your paper airplanes eventually fall
    onto the ground.

    The tricky part is that lift could not happen in a fluid or gas that did not
    also have drag. This is why people originally thought airplanes were
    impossible because they were studying the equations of fluids which
    did not have drag-type effects (zero viscosity, see Helmholtz).
  5. Aug 6, 2005 #4
    thanks! :)
  6. Aug 8, 2005 #5


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    Care to fill us in as to which ones are incorrect?

    If you believe that lift is solely generated by the pressure differential then you didn't read that thread. There are other, more predominant aspects that produce lift, i.e. fully symmetrical airfoils.
  7. Aug 11, 2005 #6


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    This is always the never ending discussion. :biggrin:
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