Pendulum question

1. Nov 2, 2005

fridsatu

I am sure this is simple to most people...but i dont understand how to show potential energy of a pendulum to be mgcostheta/2l. is there anybody that could break that down for me??

2. Nov 2, 2005

Chi Meson

First of all, it's not.

PE of a pendulum is mg [L-Lcos(theta/2)].

What's the usual formula for PE? What of the above formula is equal to the "h"?