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. The attempt at a solution How can I solve this problem? If I have a disk uniformly charged then I know how to calculate the electric field from an observation location but I don't know how to calculate the electric field when there is a foiled disk next to the plastic disk.