1. The problem statement, all variables and given/known data A charge of 2.9*10^-6C is held fixed at the origin. A second charge of 2.9*10^-6 C is released from rest at the position (1.15m, 0.550m). And the mass of the second charge is 2.10 g. At what distance from the origin does the 2.9*10^-6 charge attain half the speed it will have at infinity? 2. Relevant equations KE (final) = Potential Energy (initial) - PE (final) 3. The attempt at a solution There was a part A to this question where I figured out the speed it had at infinity. For the second part, I tried to just solve for r using the same equation but it doesn't work. Any tips?