Final answer:
In an inelastic collision, momentum is conserved but kinetic energy is not. Perfectly inelastic collisions involve objects sticking together and losing the maximum amount of kinetic energy.
Step-by-step explanation:
In an inelastic collision, momentum is conserved, but kinetic energy is not conserved. This means that the total momentum of the objects before and after the collision will be the same, but the total kinetic energy of the objects will change. In a perfectly inelastic collision, the objects stick together and the maximum amount of kinetic energy is lost.