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Homework Help: Capacitance potential

  1. May 20, 2003 #1

    Dx

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    [SOLVED] Capacitance potential

    Hello,

    I have 2 questions here to ask for help with?

    1) a .2F cap is desired. What area must the pplates have if they are to be seperated by a 2.2mm air gap?

    My formula i used with substition was C=e_o (A/d) with e_o = 8.85x10^-12.

    I rounded my answer it was 4.5 so rounded it to 5x10^7m^2 is this correct?


    2)What is the potential at a distance of 5 x 10^-10 m from the nucleus of charge +60e?
    I donno if my formula is correct? ids it V=Ed?

    I donno how to solve for this, can you help point me that way.
    Thanks!
    Dx :wink:
     
  2. jcsd
  3. May 20, 2003 #2

    Tom Mattson

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    Staff Emeritus
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    Gold Member

    Yes.

    No, that formula only works for constant, uniform electric field. What you have here is a Coulomb potential, which you should be able to find in your book.
     
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