DO NOW: You are picking up a pendulum (Clay ball on a string) as you pull the pendulum up on one side and let it fall, what types of energy are being used?

The energy used in the pendulum is the initial Potential (Mechanical) Energy, P.E. given to the Clay ball attached to the inclined and extended string by virtue of its elevated position in relation to the rest position (lower state)

The swinging of the pendulum is brought about by the dynamic equilibrium between the initial potential energy, P.E. and the Kinetic Energy, K.E., of the pendulum when it is in motion

The (total) Mechanical Energy, M.E. of the ideal pendulum is constant at all times during the motion of the pendulum and it is given by the following formula;

M.E. = P.E. + K.E.

At the top of the swing, P.E. is maximum and K.E. is zero

Similarly, at the mid (lowest) point in the swing, instantaneously, P.E. is zero and K.E. is maximum

Explanation: