Citation:
Momentum conservation states that in an isolated system (where no external forces act), the total momentum before an event or interaction is equal to the total momentum after the event or interaction.
The change in momentum of an object caused by a force acting on it for a certain amount of time.
Elastic collision: A collision where both kinetic energy and momentum are conserved.
Inelastic collision: A collision where only momentum is conserved, but kinetic energy is not conserved.