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Where does the energy come from?

  1. Sep 5, 2006 #1
    put a iron beside a magnet,then we konw the iron would be attracted toward the magnet.but where does the kinetic energy of the iron come from?
  2. jcsd
  3. Sep 5, 2006 #2
    The iron is in a magnetic field, hence it has potential energy due to its position. This becomes KE when the iron is released. The total energy, KE+PE, is conserved.
  4. Sep 5, 2006 #3
  5. Sep 5, 2006 #4

    Meir Achuz

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    You are now wrong. You were right the first time. For a permanent magnet and ferromagnetic iron, the energy considerations do work just as they would in electrostatics with a charge attractilng a polarizable object.
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