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Finding the charge of a particle given the charge of another

  1. Sep 6, 2015 #1
    1. The problem statement, all variables and given/known data
    The problem should be attached, not sure how to do part b.

    2. Relevant equations

    3. The attempt at a solution
    I figured out a, but have no idea how to do b. I was thinking of summing up the electric field vectors at point p, but there are 3 variables for Enet.

    Attached Files:

  2. jcsd
  3. Sep 6, 2015 #2


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    If you sum the field vectors, how many scalar equations will you have? How many scalar unknowns are there? List them.
  4. Sep 6, 2015 #3
    Something like this?

    E1+E2+E3 = 0

    kQ/16d^2 + kq2/9d^2 + kq3/25d^2(cos theta - sin theta) = 0

    Not sure what to do from here though..
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