- #1

Breedlove

- 27

- 0

## Homework Statement

A nonconducting wall carries charge with a uniform denisty of 8.g µC/cm

^{2}. What is the electric field 7.00cm in front of the wall? Explain whether your result changes as the distance from the wall is varied.

## Homework Equations

I'm still really new, I just registered, and trying to find the integral sign and stuff is proving to be pretty difficult

[tex]\int[/tex]EdotdA=Qenclosed/A

E=k[tex]\frac{q}{r

^{2}}r[/tex]unit vector

So Gauss's Law and the equation for the electric field, I think, are relevant. The relationship [tex]\sigma[/tex]=Q/A I think is important too. Let's throw in Coulomb's Law for good measure.

F=kqq

_{0}/(r

^{2})r unit vector

## The Attempt at a Solution

Okay, so from my understanding of Gouss's Law, you can use it to calculate the electric field around a closed symmetrical surface that surrounds the thing you want to find the electric field of. Rather, Gauss's Law is a way of counting up the electric field lines. I think I understand how to use Gauss's Law to find the electric field at a point around a sphere of charge; you can just make a Gaussian Sphere around it.

Anyway, I guess my major source of confusion is that you can't really encapsulate a wall, like if it was a rod, or if we could interpret it as a long line of charge, then we could put a cylinder around it. I think I gathered from another post that

E=[tex]\sigma[/tex]/(2[tex]\epsilon[/tex]

_{0})

I think that this is the key, but I don't know how this came about. How can this be derived from Gauss's Law or the equation for electric field?

I'm generally pretty confused, and I think I'm going to try to firm up my understanding of applying Gauss's law while I hope that someone replies.