- #1
Dustgil
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Homework Statement
Calculate the potential of a uniformly polarized sphere directly from eq. 9
Homework Equations
[tex]V(r)=k \int \frac {P(r') \cdot \hat{r}} {r^2} d\tau[/tex]
The Attempt at a Solution
P is a constant and can be factored out. Since r is taken, call the radius of the sphere R and and an arbitrary radial length l. Then by the law of cosines we can express the denominator for every volume element as.
[tex]r^2=l^2+z^2-2lzcos\theta[/tex]
This is where I'm stuck. What can I do with r hat? Nothing? I understand that its a unit vector in the direction of of the volume element to the point I'm trying to evaluate at, but I'm not sure if I need to change anything about it or not. z is constant so in theory once I have that changed I can evaluate the integral. Is there an easier way?