1. The problem statement, all variables and given/known data A uniformly charged thin ring has radius 13.0 cm and total charge 21.5 nC . An electron is placed on the ring's axis a distance 32.5 cm from the center of the ring and is constrained to stay on the axis of the ring. The electron is then released from rest. Find the speed of the electron when it reaches the center of the ring. 2. Relevant equations ∫dE = ∫k*dq*R^2*cos(θ) ∫E * dL = -ΔV z = distance from electron to center of ring r = radius of ring R = point on ring to electron 3. The attempt at a solution So at first I started off with changing ∫dE into a function of only one changing part. = kdq/R^2*cos(θ) = k*dq*z/R^3 = k*Q*z/(z^2 + r^2)^(3/2))dz = k*Q/((r^2 + z^2)^.5) = ΔV ≈ 8.85*10^-17 = ΔKE = .5mv^2 (8.85*10^-17)*2/(9.11*10^-31) ≈1.9*10^7 I've tried this problem a couple of times, and have gotten anywhere between 1.0-2.0*10^7. I know it's suppose to be around this, but if any errors could be pointed out that would be great. I don't want to lose anymore points on this problem. Thanks! Also, as a completely off related topic, is there anywhere here that gives a guideline on how to use the templates for powers and whatnot? I'm not quite sure how to use the whole , and would like to learn how to make posts more readable.