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Homework Help: Work Done by moving point charge

  1. Jan 26, 2009 #1
    Hi I think I figured it but I'm not sure.

    Here's the problem:

    How Much Work In Fig. 25-34, how much work is required to bring the charge of +5q in from infinity along the dashed line and place it as shown near the two fixed charges +4q and –2q? Take distance d = 1.40 cm and charge q = 1.6 × 10–19 C.


    I summed up the Vpotential at the point which I got 0 Volts

    Then I used W = qt(Vp-Vinfinity) = 0J. It just seems too simple to be correct.
    Last edited: Jan 26, 2009
  2. jcsd
  3. Jan 26, 2009 #2
    You image does not open. Can you describe it?
  4. Jan 26, 2009 #3
    This can't be solved without knowing the relative spacings of all the charges. The net repulsion/attraction will determine how much potential energy is stored by the work. Can you describe the particle positions using a coordinate system?
  5. Jan 26, 2009 #4
    Edit: I reuploaded the picture, thanks for your replies
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