Electric Flux Through a Square: 2.1µC @ 20 cm

[peaceandlove]

Homework Statement

A charge of 2.1 µC is 20 cm above the center of a square of side length 40 cm. The permittivity of free space is 8.85*10^-12 C^2/N*m^2. Find the flux through the square. Answer in units of N*m^2/C.

Homework Equations

The Attempt at a Solution

I really need some help with starting this problem... =(

 

[LowlyPion]

Homework Statement

A charge of 2.1 µC is 20 cm above the center of a square of side length 40 cm. The permittivity of free space is 8.85*10^-12 C^2/N*m^2. Find the flux through the square. Answer in units of N*m^2/C.

Homework Equations

The Attempt at a Solution

I really need some help with starting this problem... =(

Maybe consider constructing a Gaussian surface that is a 6-sided cube?

 

[peaceandlove]

I haven't exactly gotten used to constructing formulas for Gaussian surfaces so could you explain how to do it?

 

[LowlyPion]

I haven't exactly gotten used to constructing formulas for Gaussian surfaces so could you explain how to do it?

It may be simpler in this case than you think.

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/gaulaw.html#c1