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Homework Help: Problems with Work and Kinetic Energy

  1. Oct 9, 2004 #1
    Hey, I have been fiddling with with problem all day today and I really have no idea how to even approach it. I was wondering if anyone could help shed some light onto it for me. Any help would be greatly appreciated!

    [HRW7 7.P.042.] A skier pulled by a tow rope up a frictionless ski slope that makes an angle of 12° with the horizontal. The rope moves parrallel to the slope with a constant speed of 1.0 m/s. The force of the rope does 950 J of work on the skier as the skier moves a distance of 8.0 m up the incline.

    (a) If the rope moved with a constant speed of 2.0 m/s, how much work would the force of the rope do on the skier as the skier moved a distance of 8.0 m up the incline?
    ___________J
    (b) At what rate is the force of the rope doing work on the skier when the rope moves with a speed of 1.0 m/s?
    __________W
    (c) At what rate is the force of the rope doing work on the skier when the rope moves with a speed of 2.0 m/s?
    ________W


    Thanks so much!

    -Ashley
     
  2. jcsd
  3. Oct 9, 2004 #2

    Pyrrhus

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    What have you done?

    Do you know?

    [tex] \sum_{i=1}^{n} W_{i} = \Delta K [/tex]
     
  4. Oct 9, 2004 #3
    well Im not very good at physics (at all)

    Im not familiar with that equation I dont think we covered that in our class.

    I have no idea how to read the problem even to begin to answer it. It all makes no sense and the book my teacher uses is useless... I tried drawing out a diagram and I have tried the force=mgsin(theta) but I dont have the mass to find that and thats pretty much the only thing I know to try to do.
     
  5. Oct 9, 2004 #4

    Pyrrhus

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