Check out our wood pendulum selection for the very best in unique or custom, handmade pieces from our collection. A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced sideways from its resting, equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position. Pendulum, body suspended from a fixed point so that it can swing back and forth under the influence of gravity. Pendulums are used to regulate the movement of clocks because the interval of time for each complete oscillation, called the period, is constant. A pendulum works by converting energy back and forth, a bit like a rollercoaster ride. When the bob is highest (furthest from the ground), it has maximum stored energy (potential energy). ... So as the bob swings (oscillates) back and forth, it repeatedly switches its energy back and forth between potential and kinetic.