Recent content by Smith987

I think I solved the problem- when you consider dU as 0.5 *d(V^2 * C), this is equal to 0.5 * (V + dV)^2 * (C + dC) - 0.5*V^2 * C, which by using dv/dc= -Q/(C^2) leaads to the answer given. And pleasingly it gave me that annoying negative sign :) I would still like a pat on the back though.

Homework Statement I have been reading electricity and magnetism by Duffin in order to understand my first year EM course. So far it has been straightforward- however, I've hit a wall when it derives the force between 2 conductors (p.117 section 5.7 if you have the book!). The book says...

Aha thanks for the help guys :)

Hi guys, I really have no idea how to approach finding the particular integral for, say: f'' + 5f' + f= e^x sinx Could anyone help me? And for future reference how do you go about finding the PI for any combination of polynomials/exponentials/sinusoidals? Thanks in advance for the help!

Thanks! Makes sense now :) That's cleared up a lot for me so thanks again!

Hi all, I'm new here, I was on another forum asking this question but there was a lack of a response, so I hope you guys can help me out! Ok, so after a few weeks of grappling with the twin paradox, I finally accept that the twin that travels on the rocket and back is the one that ages less...