- #1
kittyset
- 3
- 0
Hello,
I've been struggling with this question:
Let q be a constant, and let f(X) = f(x,y,z) = q/(4pi*r) where r = ||X||. Compute the integral of E = - grad f over a sphere centered at the origin to find q.
I parametrized the sphere using phi and theta, crossed the partials, and got q, but I think there's another way using the divergence theorem, given as ∫∫E⋅ndσ = ∫∫∫ div E dV (sorry about the awkward symbol usage :/ ). I'm not sure what's going wrong with the following:
1. div grad f = div -E = div E = 0
2. ∫∫∫ div E dV = 0 ≠ q
I'm probably missing something super basic, but any hint would be a great help!
I've been struggling with this question:
Let q be a constant, and let f(X) = f(x,y,z) = q/(4pi*r) where r = ||X||. Compute the integral of E = - grad f over a sphere centered at the origin to find q.
I parametrized the sphere using phi and theta, crossed the partials, and got q, but I think there's another way using the divergence theorem, given as ∫∫E⋅ndσ = ∫∫∫ div E dV (sorry about the awkward symbol usage :/ ). I'm not sure what's going wrong with the following:
1. div grad f = div -E = div E = 0
2. ∫∫∫ div E dV = 0 ≠ q
I'm probably missing something super basic, but any hint would be a great help!