Regulus wrote:Physics test in 1 hour. Just looking back at all the problems I've done for this section, and I can't help but realize that I've actually learned a lot of new things in this class. Hooray for not wasting time/money!
Oh God, that test was hard. I didn't even expect to have to do one charge distribution problem, considering it was a 50 minute test, and there's just no time for something too involved. But there were two.
And they were both cylinders. Y'know, I could have done it easily, if they had been any other shape, like a line, ring, sphere, or sheet. But the cylinders? I freaking hate those. We only had one cylinder problem on the homework, and go figure... that was the one I never figured out how to do.
Now that I look in the book, there's nothing in there that explains how to do one of those cylindrical charge distribution problems, either. There's one little problem on a cylindrical line with a linear charge density, using Gauss's law... but that's different. This was cubic density, but with only cross-sectional data given.
Obviously, those were both Gauss's law problems, even though the problem asked for the electric field at a point, instead of the electric flux of the object. But why don't the units match? You can't just ignore the third dimension in a three-dimensional object... or can you?









