1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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
    F=mg
    W=F*d


    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

    stockzahn

    User Avatar
    Gold Member

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

    BvU

    User Avatar
    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...
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted