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Homework Help: Air friction on a A4 paper ( Classical Mechanics )

  1. Feb 18, 2009 #1
    1. The problem statement, all variables and given/known data

    How could u find the drag/friction due to air on a A4 size page dropped perpendicular to the ground. There are about 20 sheets and is dropped about waist height. The tricky thing is no instruments are aloud. Only your senses...

    2. Relevant equations

    F=-cv where c is the constant due to air friction. v is the vel and F the force of air

    3. The attempt at a solution

    have no clue because i would think u would at least need a stop watch.
  2. jcsd
  3. Feb 18, 2009 #2
    If you are given no instruments you will need to make estimates.
  4. Feb 19, 2009 #3
    what estimates? u will have c for the friction and g for the gravity.u could considers some sort of acceleration from looking at the system.could it be done???? i would think it would be of the function speed and maybe have to differentiate a few times but would not know where to start...
  5. Feb 19, 2009 #4
    Because of the lack of instrument the best that can be done is a crude estimate.The falling paper tends to rock to and fro but there doesnt seem to be a net vertical acceleration.I think you are expected to assume it reaches terminal velocity this being when the weight of the paper is balanced by air resistance.
  6. Feb 21, 2009 #5
    thanks Dadface!!!
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