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Homework Help: Pulley weight problem

  1. Oct 24, 2006 #1

    Two weights w1 and w2 are suspended from the ends of a light string over a smooth pulley. If the pulley is pulled up at the free end of the rope, then what will be the force exerted by the rope on the block?

    I can find out the tension and acceleration if the pulley was not accelerating. How do I this?

    EDIT: string
    Last edited: Oct 25, 2006
  2. jcsd
  3. Oct 24, 2006 #2


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    Does it really say light spring, or is it string?
    In any case, you need to look at the free body diagrams for the weights, recognizing that the tension is constant throughout the s(t/p)ring. If the block has negligable mass, the force exerted by the rope is twice the tension, just as it would be with no acceleration. It seems there must be more information than what you stated. You cannot find both the force and the accelerations knowing only that the weights are connected.
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