Double pendulum

A double pendulum is two pendulums connected one after the other, like a chain. The first pendulum has a weight or bob at the end of a rod, and the other pendulum is connected to the first one with a second rod. When you swing the first pendulum, it makes the second one swing, too, so both pendulums move back and forth at the same time! This teaches us about how energy moves and is transferred from one pendulum to the other.