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Homework Help: Force on a point charge

  1. Feb 23, 2010 #1
    1. The problem statement, all variables and given/known data

    2 particles of charge q and -2q are located as shown in http://s966.photobucket.com/albums/ae146/acherentia/ . A third charge Q is placed on the x axis and it is found that the total electric force on Q is zero. In which region of the figure is Q located?

    2. Relevant equations

    Coulomb's Law

    3. The attempt at a solution

    F1 + F2 = 0

    F1(q on Q) = ?

    F2(-2q on Q) = ?

    What exactly does it mean a charge of -2q? Is it the same as the charge of 2 electrons?
  2. jcsd
  3. Feb 23, 2010 #2


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    Hi acherentia! :smile:
    It just means that the second charge is minus twice the first charge …

    it could be one proton and two electrons, or just one coulomb of positive charge and two coulombs of negative charge, or any such combination. :wink:
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