Electric Field/Gauss' law of cylinder and shell

AI Thread Summary
The discussion revolves around applying Gauss' Law to a problem involving a cylindrical charge distribution. The original poster struggles to find the charge per length needed to calculate the electric field (E) and has difficulties with the problem's multiple parts. A suggestion is made to use cylindrical coordinates and consider a Gaussian cylinder to derive E in terms of charge per unit length. The importance of calculating the charge enclosed within the Gaussian surface based on the given charge density is emphasized. Overall, the conversation focuses on the correct application of Gauss' Law to determine the electric field in various regions around the cylinder and shell.
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Homework Statement


http://img244.imageshack.us/my.php?image=a1physicsmt8.png


Homework Equations


Gauss' Law


The Attempt at a Solution


It may be that I'm sick with a cold and can't think straight, but I"m not seeing any way to approach this problem using Gauss' law. I tried using a few prederived formulas, but like for the first part of this 5 part problem, I need the charge/length in order to find out E. I don't have that value, and I did try using rho as lambda, and got it wrong. I also have to find the charge at values inbetween the cylinder and the shell, outside the shell, and on the inner shell.

Some help would be nice, as I can't see how to do this by hand right now.
 
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Consider a Gaussian cylinder with radius of 2 cm. This cylinder is within the green cylindrical charge distribution. Gauss's Law is

\oint_{S}\vec{E}\cdot\vec{dA}=\frac{1}{\epsilon_{0}}\int_{V}\rho dV

Use cylindrical coordinates, the given charge density, and the fact that the electric field is parallel to your Gaussian surface's normal vector to solve this.

Note that S is the surface area of your Gaussian cylinder and V is the volume within it.
 
Using a cylindrical Gaussian surface will give E in terms of charge/unit length. So, let the Gaussian surface be

2\pi\mbox{rl}

where l is a unit length. Then the charged enclosed per unit length within this surface is the volume within the surface times the charge density for r less than the radius of the inner conductor.
 
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