Question

A simple pendulum oscillates with an amplitude of 30 degrees. If the length of the string is 1.0m. Calculate the velocity of the pendulum bob at its lowest point.

Answer 1

Well, at 30 degrees, its height is
L-Lcos30
so its potential energy is mg(L-Lcos30) and that is equal to the KEnergy at the bottom...

mgL(1-cos30)=1/2 m v^2
so calculate velocity v

Answer 2

5.66