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Increasing GPE and KE

  1. Nov 11, 2014 #1
    If i wanted to increase the gravitational potential energy of a ball do I always have to apply a force times a distance? In this case the force would be the weight of the ball and the distance would be the height.
    What if I kicked the ball upwards? I wouldn't be applying a force times a distance , but I would be giving it momentum. So my question is, I don't always have to apply a force times a distance to increase the GPE or KE of an object do I?
  2. jcsd
  3. Nov 11, 2014 #2


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    Staff: Mentor

    You always have to do work, which means applying a force over a distance. When you kick the ball, you're applying a large force over a small distance, but that distance is not quite zero. Your toe is in contact with the ball and applying some force to it for maybe one-tenth of a second, your toe is moving during that one-tenth second so covers some distance, that distance is the ##d## in ##W=Fd##.
  4. Nov 11, 2014 #3
    Excellent! Thanks a lot!
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