Help Solving Gauss' Law Homework Problem

AI Thread Summary
To find the electric field inside a sphere with a volume charge density of ρ = k/r, Gauss' law is applied using a spherical shell of radius R (where R < a). The charge enclosed is calculated by integrating the charge density from 0 to R, resulting in Q = 2πaR². The derived electric field is E = k/(2ε), which raises concerns about its constancy despite the varying charge density. The discussion highlights potential issues with integrating from the origin, as the charge density approaches infinity at r = 0. Overall, the problem emphasizes the importance of correctly applying Gauss' law in scenarios with non-uniform charge distributions.
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Homework Statement


Trying to find E field inside a sphere radius a with volume charge density rho = k/r


Homework Equations



Gauss' law

The Attempt at a Solution



I set up a spherical shell radius R (R<a)
I found the charge inside by integrating rho from 0 to R (Q = 2*pi*a*R^2)

put these infos into gauss law, got E = k/(2(epsilon))

It just seems weird that the E field inside is constant even though the volume density is not. I guess it might be because the surface area of the gauss shell increases with R but the density drops off as 1/R.

Also, integrating from the origin seems like it might be a mistake (rho -> inf as r-> 0)
 
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Rho is the volume charge density, correct? Is there something you're missing when you go to find the charge enclosed?
 


Just a point of frustration on my part, please name your thread appropriately next time - I believe the rules do specify this.
 
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