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Homework Help: Work and Force of a pulley

  1. Oct 19, 2015 #1
    1. The problem statement, all variables and given/known data
    A 60 kg load is raised by a two-pulley arrangement. How much work is done by the
    force F to raise the load 3 m if there is a frictional force of 20 N in each pulley? Note that the pulleys do
    not rotate, but the rope slides across each surface.

    I've solved the problem, I would like to know if my answer is right. Otherwise, could you please tell me where I did wrong. thanks guys!
    2. Relevant equations

    3. The attempt at a solution
    m = 60kg
    F(friction) = 20N
    d = 3m

    F=mg∕2 + 2F(friction) = (60kg×9.8m/s²)/2 + 2×20N = 334N
    W=F×2d= 334N ×2 × 3m = 2004 J
    Last edited: Oct 19, 2015
  2. jcsd
  3. Oct 19, 2015 #2


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    Gold Member

    Seems to be correct.
  4. Oct 19, 2015 #3


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    Science Advisor
    Homework Helper
    2017 Award

    And the question you want answered by PF is ?

    Note that you can get an answer to "is this right?" by handing in your homework to Teacher !
    And that it isn't PF culture to provide yes/no correct stamps, so you'll have to ask such things a bit more subtly...
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