Why does a pendulum slow down?
A pendulum consists of a string with a weight at its lower end, and its upper end attaches to a fixed point on any supporting structure. As the pendulum swings, its weight propels it from one side to the other, and it appears that this movement will continue forever–a theory known as perpetual motion–because nothing seems to get in the way of the pendulum as it moves. Certain forces, however, cause a pendulum to slow down.Potential EnergyWhen a pendulum reaches one side of its arc, the energy it possesses at that point is known as potential energy. This is created by the force of gravity pulling down on the pendulum, which causes it to swing back in the other direction.Friction Between Parts and AirThe primary reason a pendulum slows down is the effect of air resistance acting against its moving parts as it moves through the air. Air resistance can be thought of as friction between the parts of the pendulum and air molecules. The friction acts in the opposite direction of the movemen
