1. The problem statement, all variables and given/known data Find the energy required to assemble two uniform hollow spheres of charge q between radii a and b with a volume charge density roh-v. The shells are separated by a distance c. *description of picture* - two identical spherical shells with inner radius a and outer radius b separated by a distance c 2. Relevant equations dQ = 4*pi*roh-v*R dR^2 <--- "add incremental rings of charge dQ in order to assemble a hollow sphere of charge" Q of one sphere = roh-v*pi*R^3 dW = V dQ 3. The attempt at a solution I know how to do this problem with one solid sphere. I am unsure of how the second sphere and the distance c changes the problem. Do I find the potential to assemble one sphere and then double it (for the second sphere) and then multiply it by the potential of the two sphere configuration?