1. The problem statement, all variables and given/known data An electric point charge of Q1 = 5.23 nC is placed at the origin of the real axis. Another point charge of Q2 = 1.89 nC is placed at a position of p = 2.63 m on the real axis. At which position can a third point charge of q = -2.62 nC be placed so that the net electrostatic force on it is zero? 1.643 m (SOLVED) Let the sign of Q2 be changed from positive to negative. At which position can the point charge q be placed now so that the net electrostatic force on it is zero? 3. The attempt at a solution Okay so I set up k(q1)(q2)/d^2=k(q2)(q3)/(D-d)^2 where D = 2.63m I then used the quadratic and since there is no b, I used 0. I got: 7.12E-6d^2+0d-3.62E-5 and did the quadratic to get 2.25m but this is not right? Help? Thanks!!