A pendulum with a bob of mass m is oscillating on either side from its resting position A between the extremes B and C at a vertical height h above A. What is the kinetic energy K and potential energy U when the pendulum is at positions
A pendulum with a bob of mass m is oscillating on either side from its resting position A between the extremes B and C at a vertical height h above A. What is the kinetic energy K and potential energy U when the pendulum is at positions

(i) A,

(ii) B and

(iii) C?

Solutions:

I At point A, the pendulum has the most kinetic energy, whereas its potential energy is zero. As a result, K = mgh and U = 0

(ii) At position B, the potential energy increases while the kinetic energy decreases. As a result, K = 0 and U = mgh

(iii) Kinetic energy K = 0 and potential energy U = mgh at position C.