posted by Anonymous .
Suppose the rubber rod holds -3 pico-Coulomb at x=0 and the uncharged ball has +2 femto-Coulomb at x= 50mm, as well as -2 femto-Coulomb at x=55mm distance. What would be the electric Force applied to the ball?
I used the equation F=q1q2/d^2 and did two separate calcuations, one with -3picoC and 2 femtoC and another with 2femtoC at 50 and -2femtoC at 55. I added them togther and I got the value 2.3x10^-14 N which apparently isn't correct.
Can someone help me figure out what I'm doing wrong?