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Total Work Qustion

  1. Nov 16, 2014 #1
    Below is the question:


    My equation for Work Total is:

    Delta PE = Wspring + Wgravity

    However, the solution key says that the Wspring + Wgravity = 0

    I fail to understand this, why is the total work zero when there is a change in potential energy?

    Attached Files:

  2. jcsd
  3. Nov 16, 2014 #2


    User Avatar

    Staff: Mentor

    [edit: better way to say it]
    If you come up with both gravitational PE and another total PE, you end up with more energy than the spring put into the system. You're counting the GPE twice.
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