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Homework Help: Net Force of a Charge

  1. May 30, 2013 #1
    1. The problem statement, all variables and given/known data

    The drawing shows three point charges fixed in place. The charge at the coordinate origin has a?
    q1 = +8.50 µC; the other two have identical magnitudes, but opposite signs: q2 = -5.00 µC and q3 = +5.00 µC.


    (a) Determine the net force (magnitude and direction) exerted on q1 by the other two charges.

    (b) If q1 had a mass of 1.50 g and it were free to move what would be its acceleration?

    2. Relevant equations



    3. The attempt at a solution

    F12= +2.128*1023

    F13= -+2.128*1023

    cos(23°)= Fx/+2.13*10^23

    Fx= 1.96*1023

    cos(23°)= Fy/-2.13*10^23

    Fy= -1.77 *1046

    Before I go any further, I wanted to make sure I am doing this right since I am kind of rusty. If anyone could check, it would be greatly appreciated.

    Thanks in advance!
  2. jcsd
  3. May 30, 2013 #2

    Simon Bridge

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    Science Advisor
    Homework Helper

    Your attempt does not show any reasoning nor any working - so I cannot tell if you are doing this right or not.

    Note: you can show the image in the post like this:


    You look like you've maybe tried to break the forces into x and y components - but why not just draw the vectors head-to-tail? You can see by inspection how their magnitudes and directions are related - which should tell you the direction of the total force without having to do any trig.
    Last edited by a moderator: May 6, 2017
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