What makes some collisions elastic and others inelastic? a. if there is energy lost in the collision to sound, heat, etc., the collision is inelastic. b. if there is no loss of kinetic energy in the collision, it is inelastic. c. if the collision involves bouncing, it is elastic. d. if the collision involves sticking together, it is elastic.

The correct choice is (A)

If there is energy lost in the collision to sound, heat, etc., the collision is inelastic.

A perfectly elastic collision is the collision in which there is no loss of kinetic energy whereas an inelastic collision is one in which part of the kinetic energy is changed to some other form of energy in the collision. Since option A shows the same concept so it is the correct choice.

1/0.14nm = 10^10/1.4 a lot