# Search results

1. ### Electric Charge Density

Okay, that makes sense. Thanks for your help, this was driving me crazy, I couldnt figure out why units were not making sense.
2. ### Electric Charge Density

Yeah, sorry missed that. Have the \delta^3 on my paper, just forgot to type it in. I don't understand how n-D delta functions have a dimension of (length)-n, could you explain that perhaps?
3. ### Electric Charge Density

(src: Intro to Electrodynamics, Griffith, Problem 1.46a) Q: Write an expression for the electric charge density \rho (r) of a point charge q at r^'. Make sure that the volume integral of \rho equals q. Now, Closest I can seem to come up with is...
4. ### Seperation Vector

Okay, nevermind on this... Went with a totally different appraoch and things worked out nicely without having to go into spherical coordinates. Thanks again.
5. ### Seperation Vector

Wouldnt that just complicate things further? In Spherical Coordinates: \displaystyle{ \nabla = \hat{r} \frac {\partial{}{}} {\partial{}{r}} + \frac {1}{r} \hat{\phi}\frac {\partial{}{}} {\partial{}{\phi}} + \frac {1}{r sin \phi} \hat{\theta}\frac {\partial{}{}} {\partial{}{\theta}} }...
6. ### Seperation Vector

Separation Vector Let \vec{r} be the seperation vector from a fixed point (\acute{x},\acute{y},\acute{z}) to the source point (x,y,z). Show that: \nabla(\frac{1}{||\vec{r}||}) = \frac {-\hat{r}} {||\vec{r}||^2} Now, I've attempted this comeing from the approach that ||\vec{r}|| =...