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Homework Help: Electrostatics - Magnitude and direction of electric force

  1. Jan 4, 2009 #1
    1. The problem statement, all variables and given/known data
    What are the magnitude and direction of the electric force on the +2.0x10^-6 charge shown in the diagram (included in the attachment)?

    2. Relevant equations
    F = kq1q2/r^2

    3. The attempt at a solution
    I used the Ep = kq1q2/r^2 equation and plugged in the numbers but didn't get any of the provided answers and I was just wondering what I was doing wrong?

    What I did was:
    F= kq1q2/r^2
    F= (9.00x10^9)l(-6.0x10^-6)(-7.0x10^-6)l/(4.0)^2 [note: l l here means absolute value]
    F= 0.23625

    the answer I got was that, but it matches up with none of the provided answers?

    Attached Files:

    Last edited: Jan 4, 2009
  2. jcsd
  3. Jan 4, 2009 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Re: Electrostatics

    :confused: Not sure what you did here, since you were asked to find the force on the +2.0x10^-6 charge (the middle charge).

    What force does the left charge exert on the middle charge?
    What force does the right charge exert on the middle charge?

    What's the net force on the middle charge?
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