# Homework Help: Net Flux help

1. Jan 31, 2007

### dtesselstrom

1. The problem statement, all variables and given/known data
A hollow metal sphere has inner radius a and outer radius b. The hollow sphere has charge +2Q. A point charge +Q sits at the center of the hollow sphere.
Determine the magnitude of the electric field in the region r < a.
Determine the magnitude of the electric field in the region a < r < b.
Determine the magnitude of the electric field in the region r >b.
Solve in Q/(pi*Eo*r^2) units
2. Relevant equations
Net Flux=Q/Eo
Net Flux= integral(E*dA)

3. The attempt at a solution
Not really sure how to approach. I figured it was fairly straight forward since the units you solve for pretty much get rid of the calculation. I thought it would be 1 when r<a 2 for when a<r<b and 0 for r>b but none of them work and Ive used numbers around that. So I guess I need some explaining on this because I can't figure out any of the problems similar to this when it comes to net flux. So if anyone can also provide some explanation to what I am doing here that would be appreciated.