1. The problem statement, all variables and given/known data Figure 24-21 shows four pairs of charged particles with identical separations. (a) Rank the pairs according to their electric potential energy (that is, the energy of the two-particle system), greatest (most positive) first. (b) For each pair, if the separation between the particles is increased,does the potential energy of the pair increase or decrease? 2. Relevant equations U = W = (kq1q2)/r 3. The attempt at a solution For part a, I got the ranking 3,2,4,1 by subtracting the second particle from the first one. ie. (1) -2-(+6) = -8 For part b, I got 1,4 increase whereas 2,3 decrease from the equation. I haven't gotten the answers to these but I want to make sure I'm right. Thank you!