Collision two-body

Our next task is to calculate the average velocity after collision u. This calculation requires us to make some statement about the type of collision undergone by the two molecules. In an inelastic collision two bodies collide and stick together. Momentum is conserved in this collision but the kinetic energy of the bodies is not usually conserved. In an elastic collision the two bodies collide and then move apart again. Momentum must be conserved in this type of collision also but the important difference between an inelastic 13... 

Considering a binary elastic collision two bodies collide and thereafter move apart again in such a way that both the overall momentum and the total kinetic energy of the center of mass of the two bodies are conserved ([96], p. 13) [43]. 

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