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Homework Help: Electrical fields between two objects

  1. Jan 28, 2009 #1
    1. The problem statement, all variables and given/known data
    Two charges are 1m apart, the first charge is -2.5microC and the second on is 6 microC, determine the point(other than infinity) at which the electric field is zero.

    2. Relevant equations

    3. The attempt at a solution
    ok maybe i am just really overthinking the problem at hand. but for my first attempt, i simply let E=0 and set it equal to the rest of the equation(with r=1) the thing is, i do not know how to find the point. (i'm assuming i am solving for q but i don't think that is right) I just do not know how to solve for the point
  2. jcsd
  3. Jan 28, 2009 #2


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    Homework Helper

    You started off well enough. You are not solving for q; both of those are given. You are solving for something like r, except that is given, too, so that's probably what's confusing you. You have to put these charges in a coordinate system, and then give it some thought. Try to use symmetry to make this problem as simple as possible. Hint: if a point in space is 0.2 m from [itex]-2.5~\mu{}C[/itex], then how far away is it from [itex]+6.0~\mu{}C[/itex]?
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