Question

What is the difference between elastic collisions and inelastic collisions?


Elastic collisions are when the two objects are not permanently deformed or changed after the collision

Elastic collisions are when the two object stick together afterwards

In elastic collisions, the net momentum before the collision is different than the net momentum aftewards

Inelastic collisions have a different net momentum before and after the collision

Answer 1

Pick the true/false for each:

1. "Elastic collisions are when the two objects are not permanently deformed or changed after the collision" — True (ideal elastic collisions conserve kinetic energy; objects recover their shape).

2. "Elastic collisions are when the two object stick together afterwards" — False (sticking together is a perfectly inelastic collision).

3. "In elastic collisions, the net momentum before the collision is different than the net momentum afterwards" — False (for an isolated system, momentum is conserved in all collisions, including elastic ones).

4. "Inelastic collisions have a different net momentum before and after the collision" — False (momentum is still conserved in inelastic collisions; what changes is kinetic energy — some of it is converted to heat, sound, deformation, etc.).

Summary: The key difference is kinetic energy: elastic collisions conserve total kinetic energy; inelastic collisions do not. Momentum is conserved in both (if no external forces act).