Question

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

Explanation:

• In an elastic collision, kinetic energy is conserved.
• In an inelastic collision, kinetic energy is not conserved as some energy is lost (e.g., to sound, heat).
• Sticking together implies a loss of kinetic energy (inelastic).
• Bouncing doesn't necessarily define elastic (though often associated, need energy conservation).

Answer:

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