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Homework Help: What is the net work done if an object is ?

  1. Dec 12, 2011 #1
    1. The problem statement, all variables and given/known data
    What is the net work done if an object is raised 5m, carried horizontally 8m, lowered 2m, and then lowered 3m if there is no friction?

    2. Relevant equations

    W=F x d (force times distance)
    work done overcoming gravity: W=mgh (mass times gravity times height)

    3. The attempt at a solution
    no idea! since we don't have the mass
  2. jcsd
  3. Dec 12, 2011 #2


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    Homework Helper

    Those questions usually mean "work accomplished" rather than work "done". Your muscles would have to do some work to carry the mass, but that doesn't accomplish any change in the potential energy of the mass. In this case, the mass ends up at the same height as it started so no work is accomplished or stored in some useful form of energy.
  4. Dec 12, 2011 #3
    net work done ON the object, not by your muscles.
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