The pendulum swinging back and forth involved the transformation between kinetic and potential energies

A SIMPLE PENDULUM

The simple pendulum (above) also illustrates much of the same features of the conservation of energy. A simple pendulum consists of a mass (called a bob) attached to a light string and supported so that the bob ca swing back and forth, or oscillate, freely. The pendulum is called "simple" because majority of the swinging mass is in the bob. The string, for all particle purposes, can be abandoned.

The pendulum can be set in motion by raise the bob to one side and releasing it. The bob will swing back and forth with periodic motion, and the angle of the swing will never exceed the previous one. The length of the string has a great affect on the pendulum. The shorter the string is, the more frequency a pendulum will have. However, the weight of the bob and the amplitude will not affect the frequency of the pendulum.

Following are some definitions for the pendulum: