I figured it out. I'm too lazy to type out the solution, and since I know this could potentially help someone in the future searching for it, I'll give you the basic steps:
1. Change the integral I had in the last line to cylindrical coordinates.
[From here it's just tricky calculus]
2. Do the...
Homework Statement
A point charge q is a distance a>R from the axis of an infinite solenoid (radius R, n turns per unit length, current I). Find the linear momentum and the angular momentum in the fields. (Put q on the x axis, with the solenoid along z; treat the solenoid as a nonconductor, so...