What Is a Pendulum?

A pendulum is anything that hangs from a fixed point and swings back and forth. A playground swing is a pendulum! A grandfather clock has a pendulum that swings tick-tock, tick-tock to keep time.

The simplest pendulum is just a weight tied to a string. When you pull the weight to one side and let go, it swings to the other side, then back again. One complete swing (over and back) is called a period.

Here is a great science question: what changes how fast a pendulum swings? Does the length of the string matter? Does the weight matter? Does how high you pull it matter? Let us find out through experiments!