1. I think this should an easy one: The problem statement, all variables and given/known data Consider an insulating sphere of radius R centered on the origin with total charge Q uniformly distributed throughout the volume of the sphere. What is the electric feild E inside the sphere at a distance r from the origin? (i.e. r<R) 2. Relevant equations They list Vshpere=4/3 ∏r^3 and Asphere=4∏r^2 I know E=kQ/r^2=f/q 3. The attempt at a solution Multiple choice and I thought it was just E=kQ/r^2. Answer is really E=kQr/R3. Where did R^3 come from? I have to be missing an equation from my notes.. I must have to somehow incorporate the volume.