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Energy extraction help requested

  1. May 22, 2009 #1
    My basic question is this. Can usable energy be extracted from a mechanism that has force only, no movement. Here is an example. You press a hard cover book against a wall. You now lean into the book thus there is static force against the wall. There is no movement, just force. This happens over and over, you release the force and re-apply the force over and over, the book never moving to or from the wall. How can one extract the force and convert it into usable energy? I realize energy can not be created, only converted. How can the weight of my body exerting force to the wall via the book be extracted without movement?
     
  2. jcsd
  3. May 22, 2009 #2

    Mapes

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    Hi zydubion1, welcome to PF. The basic answer is: no, energy cannot be extracted from force without displacement.
     
  4. May 22, 2009 #3
    Thanks Mapes. Next question: If one could get a very small displacement, say 0.25mm, what are some of the best ways to extract usable energy when such small displacement is available?
     
  5. May 22, 2009 #4

    Mapes

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    Hmm... the first thing that comes to mind is piezoelectricity, which employs very small displacements. Alternatively, a lever might be used to amplify the displacement for use with other types of generators.

    You might also get some ideas http://en.wikipedia.org/wiki/Energy_Harvesting" [Broken].
     
    Last edited by a moderator: May 4, 2017
  6. May 22, 2009 #5
    Mapes...Thanks for your help. I will start doing some homework based our your suggestions.
     
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