OAR Mechanical Comprehension Practice Exam – Study Guide & Prep

A pendulum swings back and forth due to the force of gravity acting on it. When a pendulum is released from a certain height, it will convert its potential energy at that height into kinetic energy as it swings downward. At the lowest point of its swing, all the potential energy is converted into kinetic energy, allowing it to swing back up to the same height from which it was released.

This means that a pendulum can reach a maximum height equal to its starting height but cannot exceed it without additional energy added. Therefore, it will rise to exactly the same point where it started before gravity pulls it back down again, demonstrating the principle of conservation of energy in a closed system.