Pendulum

A pendulum is something that moves back and forth - like a swing or a clock. It is made up of a weight called a bob that is connected to a string or rod. When you push the pendulum, the bob swings back and forth or side to side in a regular back and forth 'pendulum' motion. The most recognizable example of a pendulum could be a grandfather clock. Whenever you walk past the clock, you can see the 'pendulum' moving back and forth keeping perfect time.