Simple harmonic motion

1. Oct 12, 2006

rhyso88

hey guys, just hpoping sum1 could point me in the rite direction....i cant wrk out how to proove v^2=n^2 (A^2-x^2) from

v dv/dx = -n^2x

obviously you hav to integrate...but i dont know how they get the A into the equation??

what i hav tried is intergating both sides with recpect to x first

v dv/dx x = (-n^2x^2)/2 and given we know dv/dx . dx/ dt = -n^2x and v = dx/dt the sub in to have

.....well it brings me no where actually hence this post

thanks for you help

2. Oct 12, 2006

Eds

Integrate both sides wrt x, giving you:

integral v dv = -n^2 integral x dx. This, with intial conditions( v=0 at x = a), gives you the required quadratic.

Next up,

learn to spell and write English.

3. Oct 12, 2006

rhyso88

well thanks for that, and im sorry about the english....just typing quickly and didn't realise correct grammer is required in a Maths forum....but never the less thanks