Compound Pendulum

Here is a tool to help calculate a coumpound Pendulum

Compound Pendulum Calculator

Rod

Total length (mm)400

Above pivot (mm)200

Rod mass (g)91

Weights

Bob mass (g)150

Top weight (g)112

Top weight pos (mm)175

Period T

—

seconds

Equivalent length L

—

Beats per minute

—

swings/min

0s—4s

For the full mathematical derivation,the Wikipedia article on pendulum is an excellent reference.