1. The problem statement, all variables and given/known data Figure a -q1(+)------q2(+)- x (Just the X axis with two positively charged particles at the opposite ends of it, basically) The figure shows two positively charged particles fixed in place on an x axis. The charges are q1 = 1.60 x 10^-19C and q2 = 3.20 x 10^-19C, and the particle seperation is R = 0.0200m. What are the magnitude and direction of the electrostatic F12 on particule 1 from particle 2? 2. Relevant equations I have the formula for the net force and know how to apply it to get the magnitude. However, I'm drawing a blank on my earlier Physics stuff and have forgotten how to obtain the direction. (I know that given the one-axis setup it should be obvious, but would like to know the equation/formula for future use.) 3. The attempt at a solution See above. Like I said, I've got the magnitude correct, but have forgotten how to obtain the direction. Could someone help me brush up on this basic part?