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Homework Help: Need help with a problem

  1. Jul 22, 2005 #1
    A skier of mass 64 kg is pulled up a slope by a motor-driven cable. How much work is required to pull him 80 meters up a 30 degree slope (assumed frictionless) at a constant speed of 3.1 meters/second? [answer is to be in joules]

    Ok, so the equation I am using is W = (Fcos(theta))*delta x

    I tried using the values above and I've done it over and over and still came up with the same number.

    W = ((3.1*64)*cos30)*80

    = 13745.6

    Am I missing something obvious? Thanks in advance for any helpful suggestions.
  2. jcsd
  3. Jul 22, 2005 #2


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    Homework Helper

    If there was no slope, a force of what magnitude would be required to keep up a constant speed?
    And as dW = F dx, how much work would be required for the 80m trip?

    Hope this helps you figure out what you did wrong :).
    Last edited: Jul 22, 2005
  4. Jul 22, 2005 #3
    Ok, I got it . . .Thank you.
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