A pendulum is oscillating on either side of its rest position. The correct statement is :

1. It has only the kinetic energy at its each position.
2. It has the maximum kinetic energy at its extreme position.
3. It has the maximum potential energy at its mean position.
4. The sum of its kinetic energy and potential energy remains constant throughout the motion.

A simple pendulum while oscillating rises to a maximum vertical height of 7 cm from its rest position where it reaches its extreme position on one side. The mass of the bob of simple pendulum is 400 g and g = 10 m/s². The total energy of the simple pendulum at any instant while oscillating is:

1. 0.28 J
2. 2.8 J
3. 28 J 
4. 28000 J

A body falls freely under gravity from rest. Name the kind of energy it will possess

(a) At the point from where it falls.

(b) While falling

(c) On reaching the ground.

State the Principle of conservation of energy.