1. The problem statement, all variables and given/known data 2. Relevant equations Possions Equation and boundary conditions... 3. The attempt at a solution First Part that I think is right... However when I try and apply the boundary conditions ie V(a)=V(r)=0... I can't get the answer! And for the last part I need to use Gauss's Law in integral form. Any help on where I am going wrong?