1. The problem statement, all variables and given/known data Solve for the Electric force exerted on a Particle a distance z above a uniform ring of charge Q. Determine the potential energy of the charge where the charge lies directly in the center. 2. Relevant equations F=kq1q1/r^2 3. The attempt at a solution Knowing E=F/q I just solved for E then multiplied it by the charge q. resulting in E=kQz/(z^2+a^2)^3/2 thus, F=kqQz/(z^2+a^2)^3/2 Now, I'm not sure about how to go about expressing the potential energy. My intuition tells me to do Work=Potential Energy, so, W= integral of[F(dot)dl] I'm not sure where to go from here because I'm not sure as to what I should make dl.