# Gauss law

1. Sep 20, 2009

### nogoodaatphys

1. The problem statement, all variables and given/known data
there are two nonconducting spherical shells fixed in place. shell 1 has uniform surface charge density 6.0 uC/m^2 on its outer surface and radius 3.0cm. shell 2 has uniform surface charge density 4.0 uC/m^2 on its outer surface and radius 2.0cm. the shell centers are separated by l=10cm. in unit vector notation, what is the net electric field at x=2.0cm.
There is a picture that shows shell 1 with it's center at the origin, and shell 2 centered at (10,0) (because l=10)

2. Relevant equations
gauss' law, but not sure exactly what form.

3. The attempt at a solution
Well I'm unsure what to do, but I solved for the electric field created by both shells.
Shell 1=6*10^7
Shell 2= 9*10^7 (ignoring the units for the moment)

ok so I have that, but I have no idea how to determine the net field at any given point. can anyone help me get started? Thanks.

2. Sep 21, 2009

### gabbagabbahey

Well, the first step would be to put your two individual electric fields into unit vector notation (they are vector fields after all!), after that....what does the superposition principle tell you?