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Homework Help: Work on an Inclined Surface

  1. Aug 25, 2008 #1
    1. The problem statement, all variables and given/known data
    A man pulls a 10 kg box across a smooth floor with a force of 87 newtons at an angle of 24 degrees and for a distance of 76 meters. How much work, to the nearest joule, does he do?

    If the floor in the previous question is angled upward at 10.6 degrees and the man pulls the box up the floor at constant speed what is the work he does to the nearest joule?

    2. Relevant equations

    W=f(cos theta)d

    3. The attempt at a solution
    The first part i achieved and got correct, which is 6040 j. I have no idea how to do the second part. Please help!
  2. jcsd
  3. Aug 25, 2008 #2

    Chi Meson

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    Homework Helper

    Since the speed is not changing, the work is equal to the change in gravitational potential energy. Actual distance doesn't matter, only the change in height.
  4. Aug 25, 2008 #3
    So it is being displaced 1.83 m veritcally. I Figured this out by the law of sines and a simple right triangle. What is the next step to solving this?
  5. Aug 25, 2008 #4


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    The work going into the change in gravitational potential is the weight times the height. In this case it is mg*h.
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