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Homework Help: Work Problem (Urgent)

  1. Oct 6, 2008 #1
    How much work does an elevator motor do to lift a 500 kg elevator a height of 50 m?

    attempt: W = F.S.Cos90 = 0 J

    but i think its not right..... Please help some1?
     
  2. jcsd
  3. Oct 6, 2008 #2

    Hootenanny

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    Why is the angle between the force and the displacement 90o?
     
  4. Oct 6, 2008 #3
    is tht suppose to be 0 then?
     
  5. Oct 6, 2008 #4

    Hootenanny

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    Well, in which direction is the force applied? And in which direction is the elevator moving?
     
  6. Oct 6, 2008 #5
    upwards...

    so is tht going to something like W = mg x 50m x cos0
     
  7. Oct 6, 2008 #6

    Hootenanny

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    Assuming that the elevator does not accelerate, that would be correct.
     
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