State the Principle of conservation of energy.

What do you understand by the conservation of mechanical energy? State the condition under which the mechanical energy is conserved.

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?

Name the type of energy possessed by the bob of a simple pendulum when it is at

(a) the extreme position,

(b) the mean position, and

(c) between the mean and extreme positions.