1. The problem statement, all variables and given/known data A hollow sphere of outer radius R2 and inner radius of R1 carries a uniform charge 2Q. The sphere is then cut in half to create a hemispherical shell of charge Q. Calculate E at the center point (origin) P. 2. Relevant equations equation of a hollow sphere = 2/3π(r2-r1) Gauss' Law ∫E dot dA surface area hemisphere = 2πr^2 3. The attempt at a solution Well, I know this is an integration problem and that I am better off integrating with polar coordinates and that I will be integrating from 0-->π as my lower and upper integral bounds. But in all honesty I haven't had much fortune setting the integral up. The set up is the help I am asking for.