1. The problem statement, all variables and given/known data A large, thin plastic disk with radius R = 1.1 meter carries a uniformly distributed charge of Q = -7e–5 C. A circular piece of aluminum foil is placed d = 3 mm from the disk, parallel to the disk. The foil has a radius of r = 6 cm and a thickness t = 1 millimeter. a. Find the net electric field at the center of the foil. b. Calculate the magnitude q of the charge on the left circular face of the foil. 2. Relevant equations E = 1/(4*∏*ε)*q/r^2 3. The attempt at a solution I know that the answer to part (a) is 0, because a conductor will not have an electric field inside of it. I also know that the charge on one side of the foil disk will be equal and opposite to the charge on the other side, since the disk has a neutral total charge. I'm just unsure of exactly where to go from there. Should I use force equations, since I know that the charges are at rest? Or is there something I know about the electric field that I can use?