The Simple Pendulum
A pendulum is one of the simplest and most fascinating systems in physics. It consists of a small mass (called the bob) attached to a string or rod that is fixed at one end. When the pendulum is displaced from its resting position and released, it swings back and forth in a regular motion known as oscillation. Although it is very simple, it is surprisingly engaging to watch and experiment with.
How Does a Pendulum Move?
The motion of a pendulum is caused by gravity. When the bob is pulled to one side, gravitational force accelerates it toward the lowest point of its path. As it passes this point, it continues moving due to its inertia, slowing down until gravity pulls it back again. This repeating motion continues until energy is lost due to air resistance and friction.
Why Are Pendulums Important?
Pendulums have played a key role in the history of science. They were used in early clocks, helped scientists understand oscillatory motion, and are still used today in seismology, engineering, and physics education. Use the interactive pendulum demo on this page to explore how changing the length or starting angle affects the motion of the pendulum.