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Homework Help: Energy of Capacitor arg.

  1. Mar 1, 2009 #1
    1. The problem statement, all variables and given/known data

    An dielectric-filled parallel-plate capacitor has plate area A and plate separation d. The capacitor is connected to a battery that creates a constant voltage V . The dielectric constant is K.

    The capactor is now disconnected from the battery, and the dielectric plate is then slowly removed the rest of the way out of the capacitor. Find the new energy of the capacitor, U3.

    2. Relevant equations
    not sure i think this is my problem`


    3. The attempt at a solutionhelp?
    cannot depend on C apparently
     
  2. jcsd
  3. Mar 1, 2009 #2

    G01

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    Homework Helper
    Gold Member


    The reason the energy changes is because the capacitance changes when the dielectric constant changes.

    How does the capacitance depend on the dielectric constant?
     
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