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jesuslovesu
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Homework Statement
There is a charge density rho that exists in a spherical region of space defined by 0 < r < a.
[tex]\rho (r) = Ke^{-br}[/tex]
How do you find the electric field if a charge density varies as such?
The Attempt at a Solution
I found Q total = [tex]\int \int \int \rho dV[/tex]
Now I need to find E.
My real question is can I just put Q (as a function of r) into E = kQ/r^2? Or do I need to reevaluate the integral using dq = [tex]\rho r^2 sin(\theta) dr d\theta d\phi[/tex]
I get two different answers, (and I would have thought they should be the same) so which method is correct? I would have thought either would work.
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