# Fkux Out of a Cube

1. Sep 8, 2009

### grandprix

1. The problem statement, all variables and given/known data

A point charge of magnitude q is at the center of a cube with sides of length L.

Part A
What is the electric flux Phi through each of the six faces of the cube?
Part B
What would be the flux $$\phi$$through a face of the cube if its sides were of length L1?

2. Relevant equations

$$\phi$$=Ea cos theta

$$\phi$$ = q/Eo

3. The attempt at a solution

Not sure of where to begin. Can someone show me how to tackle this?

2. Sep 8, 2009

### ideasrule

Use Gauss' law. Remember that since the charge is at the cube's center, and all of the cube's sides are identical, the flux through one side is one-sixth the flux through the whole thing.

3. Sep 8, 2009

### grandprix

(1/6)$$\epsilon$$0/q?

4. Sep 9, 2009

### ideasrule

Close, but q is supposed to be on the top and epsilon at the bottom.

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