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Homework Statement
We have a uniformly charged, nonconducting sphere (charge per volume,ρ, and radius, R). Then a uniformly charged ruler (charge per length,λ, and length, d) is aligned radially almost touching the surface of the sphere. Determine the net force experienced by the ruler.
Homework Equations
∫E⋅dA=Q_{enclosed}/ε_{0}
I think thats all...
The Attempt at a Solution
I drew my gaussian surface like Gaussian surface.jpg
∫E⋅dA=Q_{enclosed}/ε_{0}
ρ=(Q/V)=Q/(4/3)πR^{2}→Q=ρ(4/3)πR^{2}
A=4πR_{1}^{2}
∫E⋅dA=Q_{enclosed}/ε_{0}→E4πR_{1}^{2}=ρ(4/3)πR^{2}/ε_{0}
E=ρR^{2}/3ε_{0}R_{1}^{2}
Now I have the electric field of the sphere at its surface
When I place a ruler almost touching the sphere aligned radially im not sure what to do... The ruler also has an electric field which we could calculate using gauss's law (the shape would be a box?). I know the spheres electric field interacts with the charged ruler...
Any help would be appreciated!
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