The mass at the end of a simple pendulum actually moves the fastest at the lowest point of its swing. This is known as the amplitude of the pendulum's motion. As the pendulum swings back and forth, the mass accelerates towards the lowest point due to gravity. At this point, all the potential energy is converted into kinetic energy, resulting in maximum speed. As the pendulum reaches the highest point of its swing, the velocity decreases until it momentarily stops before beginning its descent again.
