(a) State and explain the law of conservation of energy with an example ?
(b) Explain how, the total energy a swinging pendulum at any instant of time remains conserved. Illustrate your answer with the help of a labelled diagram.

Explanation

Law of conservation of energy states that energy can neither be created nor destroyed but it can be transferred from one form to another . The total energy before and after transformation remains the same
Let a body be at position a from the ground leave. It has potential energy P.E. When the body falls down and reaches in the middle P.E. = K.E and when the body is just about to touch the ground its K.E. `gt` P.E. This shows that P.E. is getting transferred into kinetic energy. However, the sum of the P.E. and K.E. of the object would be the same at all points