# Homework Help: Infinite sheets of charge w/ conducting slab

1. Feb 17, 2009

### rgalvan2

1. The problem statement, all variables and given/known data
Two infinite sheets with surface charge density σ1 and σ2, respectively, are oriented perpendicular to the x-axis. An infinite, conducting slab of thickness a is placed between the charged sheets as shown in the figure. The conducting plate has a net charge per unit area of σC.

σ1=8.85$$\mu$$C/m^2
σ2=1.5$$\mu$$C/m^2
σC=-3$$\mu$$C/m^2
a=2cm

2. Relevant equations
E=$$\sigma$$/2$$\epsilon$$0

3. The attempt at a solution

I figured since the magnitude of the electric field is not determined by displacement, I could just use the above equation. The only problem it that the conducting slab has different surface charge density on each side and I'm not sure how to start this. I have an exam tomorrow so any help is greatly appreciated!

2. Feb 17, 2009

### LowlyPion

What are you asked to find?

3. Feb 17, 2009

### rgalvan2

Oops sorry:
Calculate the x-component of the net electric field at x = 0.
I figured that part out though.
The next part asks to calculate the surface charge density on each side of the slab. I'm not sure how to do that. I do know that both sides need to equal the total surface charge density of the slab. Is that right?