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Homework Help: Magnitude/direction of point charges

  1. Sep 3, 2011 #1
    1. The problem statement, all variables and given/known data

    (a) Find the magnitude and direction of the net electrostatic force exerted on the point charge q3 in the figure below. Let q = +1.5 µC and d = 27 cm.


    2. Relevant equations

    3. The attempt at a solution

    I found Fx = 1.7 N and Fy = 3.3 N. So the total magnitude was 3.3 N. This part was correct, however when I tried to find the magnitude usting tan^-1(Fy/Fx) = tan^-1(3.3/1.7) = 62.74 degress the answer is wrong. It says I'm within 10%, but still wrong. I don't understand why. Please help
  2. jcsd
  3. Sep 3, 2011 #2


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    If Fx = 1.7 N and Fy = 3.3 N , then the magnitude of F cannot be 3.3 N

    Show your work so we can help find where you're going wrong.
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