Answer carefully with reasons
(i) In an elastic collision of two billiard balls, is the total kinetic energy conserved during the short time of collision of the balls i. e. when they are in contact?
(ii) Is the total linear momentum conserved during the short time of an elastic collision of two balls?
(iii) What are the answer to (i) and (ii) for an inelastic collision?
(iv) If the potential energy of two billiard balls depends only on the separation distance between their centres, is the collision elastic or inelastic? (Note: We are talking here of potential energy corresponding to the force during collision, not gravitational potential energy.)