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Homework Help: Work needed to move a point charge

  1. Jul 10, 2012 #1
    1. The problem statement, all variables and given/known data

    A +30μC charge is placed 32cm from an identical charge. How much work would be required to move a +0.50μC test charge from a point midway between them to a point 10cm closer to one of the charges.

    2. Relevant equations
    W = qV
    V = kQ/r

    3. The attempt at a solution

    Tried solving with +30μC as the Q value, r as 0.32m, and q as the test charge but I'm getting this wrong. The answer is 1.08 Joules. I know that the work done = ΔPE between the two locations, but I'm not sure how to calculate this given that BOTH charges on the ends are pushing it away....
  2. jcsd
  3. Jul 10, 2012 #2


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    What is the electric potential, due to the two +30μC charges, at a point midway between them and at a point 10cm closer to one of the charges.
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