Flux of a cube

stylez03

1. The problem statement, all variables and given/known data
A point charge of magnitude 9.10 nC is at the center of a cube with sides of length 0.685 m.

What is the electric flux through each of the six faces of the cube?

What would be the flux Phi_1 through a face of the cube if its sides were of length 0.250 m?

2. Relevant equations
4*pi*Q


3. The attempt at a solution

I tried 4*pi*9.10 which equals 411 and it says I'm off by an additive constant

I know to do part2, the flux must be found for part1 but i'm not sure if i'm applying gauss's law correctly, I know that you can use symmetry to solve these cube problems but I haven't had a decent example of this type of problem and we already have hw on it.

Doc Al

Hint: What's the total flux through any closed surface that surrounds a charge Q? Once you find the total flux, then use symmetry to find the flux through each side of the cube.

stylez03

Is the flux on any surface that surrounds a charge Q => Qenclosed / Eo

Doc Al

Yes it is.

stylez03

Though with this, knowledge, I'm still not sure how to figure out the flux on each side of the cube.

Doc Al

Start by figuring out which side has the most flux passing through it.

muchoboosto

hummm is it Q/Eo/6?