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Homework Help: Charges laying on the x-axis

  1. May 6, 2012 #1
    1. The problem statement, all variables and given/known data
    Charges q and -Q lie on the x axis at x = 0 and x = d respectively. Charge -Q has a greater magnitude than q. In which region or regions on the x axis is there a position where the electric field is zero?

    A) x < 0
    B) x < 0 and x > d
    C) 0 < x < d and x > d
    D) x > d
    E) 0 < x < d


    2. Relevant equations
    E=kq/r^2


    3. The attempt at a solution
    Not too sure where to start...
     
  2. jcsd
  3. May 6, 2012 #2

    tiny-tim

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    Homework Helper

    hi kimberlyann9! :smile:
    the electric field is zero if the total force on a charge is zero

    we may as well assume the charge is positive

    let's start with x > d …

    how does the force from q compare with the force from Q, and are they in the same or opposite directions? :smile:
     
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