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Homework Help: Counter rotation theory problem

  1. Nov 28, 2011 #1
    1. The problem statement, all variables and given/known data
    A meter stick rests on two counter-rotating wheels. The left wheel rotates clockwise while the right wheel rotates counter-clockwise. There is friction between the meterstick and each wheel. The meter stick begins off-center to the right. What is the resulting motion of the meter stick?

    3. The attempt at a solution

    Wouldn't the meter stick simply just not move because the two wheel velocity cancel one another? but I got it wrong.

    would it be The stick will be sent off the wheels to the right?
    because the stick was off-center to the right at first?

    or would it be The stick will oscillate back and forth?
    or Nothing can be said about the stick's motion?
    or The stick will be sent off the wheels to the left?

    I'm quite confused
  2. jcsd
  3. Nov 28, 2011 #2
    If the wheels rotated slowly the stick would be balanced between the wheels. Make the following to prove it to yourself,

    Attached Files:

  4. Nov 28, 2011 #3
    i tried to do the experiment, but it simply wont work because when i put the ruler off-centered to the right the ruler keep falling. however, i tried to do it when the ruler is centered, and the result is that the ruler doesnt move anywhere if i rotate both of the wheels with same speed. which means that the ruler stays on the same spot, but again it's not the answer.
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