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Homework Help: How to find electric potential at a point?

  1. Mar 14, 2010 #1
    1. The problem statement, all variables and given/known data

    Three charges are arranged as shown.
    Find electric potential energy at reference point (the one that's circled)
    How much work would it take to bring in a charge of 1.25 µC from infinity to that point?


    2. Relevant equations

    V=kQ/r

    Eel=QV


    3. The attempt at a solution

    So, first I calculated the voltage from the 1.85 µC charge and it came out to about 254,000 V
    I did the second charge the same way, the one that's at an angle, and got around 321,000 V.
    Then I calculated the net voltage from the points using vectors, and the net came out to be 218,000 V.

    So, that's the first part. However, I'm not very sure about this, since my friend is getting something else for the same problem. I know that once I get the voltage right, I can use Eel=QV to find the work needed
    So, could anyone tell me if I'm doing the first part right please?
     

    Attached Files:

  2. jcsd
  3. Mar 15, 2010 #2

    ehild

    User Avatar
    Homework Helper

    Voltage is a scalar quantity.

    ehild
     
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