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Homework Help: Elevator problem

  1. Feb 23, 2007 #1
    A system of pulleys is used to lift an elevator that weighs 3900 newtons. The pulley system uses 9 ropes to support the load. How far would 10700 joules of input work lift the elevator? Assume the pulley system is frictionless.

    2. Relevant equations
    w=fd
    f=ma
    w=mg

    3. The attempt at a solution
    w=fd
    10700=fd
    and so i tried to solve for f using f=ma...i found m using w=mg (3900=m*9.81=397.55) but we're not given the acceleration so i'm stuck!
     
    Last edited: Feb 23, 2007
  2. jcsd
  3. Feb 24, 2007 #2
    You have the weight of the elevator. So f=3900N? Try that.
     
  4. Feb 24, 2007 #3
    then what do i do with the 9 because there are 9 ropes?
    ...maybe multiply it??
     
  5. Feb 24, 2007 #4
    nvm i got it...you just ignore the 9 ropes
     
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