# Homework Help: Coulumb's Law problem

1. Sep 14, 2010

### noname1

In the figure atatched, the particles have charges q1 = -q2 = 233 nC and q3 = -q4 = 201 nC, and distance a = 5.5 cm.

For the following questions, take right to be the +x direction and up to be the +y direction.

(a) What is the x component of the net electrostatic force on particle 3?

(b) What is the y component of the net electrostatic force on particle 3?

I have all of my work attached and i cant figure out where i have my error

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Last edited: Sep 14, 2010
2. Sep 14, 2010

### kuruman

Your error is in not taking into account the negative charges, namely q2 = -233 nC and q4 = -201 nC. I suggest that you draw three arrows on particle 3, one for each force acting on that charge. Pay attention to the signs of the charges because they decide which forces are attractive and which are repulsive. Break the arrows into components after you have drawn them in the figure.