A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced sideways from its restingequilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position. When released, the restoring force combined with the pendulum's mass causes it tooscillate about the equilibrium position, swinging back and forth. The time for one complete cycle, a left swing and a right swing, is called theperiod. The period depends on the length of the pendulum and also on the amplitude of the oscillation. However, if the amplitude is small, the period is almost independent of the amplitude.