Pendulum

physics · motion · gravity · time

Weight and swing. A pendulum is simply a heavy object hanging from a fixed point that can swing freely side to side. Gravity pulls it back toward the middle every time, making it rock back and forth in a smooth, steady motion.

Perfect timekeeper. The time it takes a pendulum to swing all the way left, then all the way right, and back to where it started is called its period. This period stays almost exactly the same every single swing, which is why pendulums were used in old clocks to measure time super accurately.

Length matters most. A longer pendulum swings slower and has a longer period, while a shorter pendulum swings faster and has a shorter period. The heaviness of the weight doesn't change the period much, but the length does.

Restoring force at work. Gravity is always pulling the pendulum back toward its resting spot in the middle. This invisible push is called the restoring force, and it's what keeps the pendulum swinging in that beautiful, balanced pattern.

Found everywhere. Pendulums show up in grandfather clocks, playground swings, and even in the way buildings sway slightly in the wind. Scientists also use pendulums to study gravity and motion.