1. The problem statement, all variables and given/known data The electric potential difference due to a point charge is 4.8 V at a distance of 4.2 cm from the charge. What will be the electric potential energy of the system if a second charge of +6.0 μC is placed at that location? 2. Relevant equations V = (EQ)/q V = kq/r ΔV = W/q 3. The attempt at a solution I've tried all three equations but none of them give me the right answer. I try to find the charge of the first point step 1. 4.8 = kx/.042 step 2. .042(4.8) = kx step 3 (.042(4.8))/k = x step 4 = 2.24 * 10^-11 (that seems like a ridiculously small number, most charges are 10^-6. Adding 6*10^-6 will do nothing to the number, so I must be doing something wrong. I just can't figure out what. Even if I do get the right number and I add the charge I can't figure out what equation to use next.