1. The problem statement, all variables and given/known data Two small insulating spheres with radius 5.50×10−2 m are separated by a large center-to-center distance of 0.510 m. One sphere is negatively charged, with net charge -2.20 \mu C, and the other sphere is positively charged, with net charge 4.05 \mu C. The charge is uniformly distributed within the volume of each sphere. Calculate E_1, the magnitude of the electric field at the midway point due to the sphere with charge -2.20 \mu C only. 2. Relevant equations 3. The attempt at a solution I tried to use q/4pi(espolon not)r^2 but im not sure my radius is right because I have used half the distance for the distance and the radius of the sphere for the distance.