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Homework Help: Speed of electron

  1. Feb 23, 2008 #1

    tony873004

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    Science Advisor
    Gold Member

    ** Edit: Nevermind. I figured it out using the Work Energy theorem.

    An electron is released from rest 1.0 cim above a uniformly charged infinite plane with a charge density of 10-9C/m2. What is the speed of the electron when it hits the plane?

    my attempt:
    Potential energy when it is released= kinetic energy when it hits.

    kqQ/r = 0.5 mv2

    isolate v:

    [tex]
    v = \sqrt {\frac{{2kqQ}}{{m \cdot r}}}
    [/tex]

    This would work if I was given 2 point charges, but how do I do this with a charge density and a point charge?
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
    Last edited: Feb 23, 2008
  2. jcsd
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