1. The problem statement, all variables and given/known data Imagine that a particle with positive charge +q is placed on the x axis at x=+a and a particle with negative charge -2q is placed on the x axis at x= -a. Find the potential at all points along the y axis. 2. Relevant equations delta phi = -E dot dr 3. The attempt at a solution This isn't a homework problem, it's just a problem in the book i'm working on to get a better understanding of electric potential. I was wondering if someone could explain electric potential to me, and i figured the easiest way would be with a problem. The answer is given in terms of k, q, a, and y. I know that had the it been -q instead of -2q the answer would be zero, but I am not sure how the physics works when it is -2.