# Collision of bodies of different materials and Coefficient of Restitution

When two bodies collide, then at the time
of impact, they deform each other. Their kinetic energy increases the elastic
potential energy of the bodies due to deformation, i.e. if bodies are elastic
in nature. In the process later, this elastic potential energy is again
released, and increases the kinetic energy of bodies. If the bodies are elastic,
then whole energy of system remains conserved and if bodies are partially
elastic or inelastic, energy dissipation takes place. The final kinetic energy
of system is less than initial kinetic energy of the system.

Follow the video below to understand the
process in detail –https://youtu.be/9CiJ25L5BkQ

The amount of energy being dissipated
depends upon the type of body material used in collision. The degree of
elasticity is also measured in terms of another constant factor called Coefficient of Restitution, it defined
as the ratio of relative velocity of separation to relative velocity of
approach of the bodies undergoing collision.

For numerical analysis of collision of
bodies coefficient of restitution is a very important parameter using which we
will also understand how to evaluate the final velocities of colliding bodies
in forthcoming articles. First to understand in detail about Coefficient of
Restitution, see the video below –https://youtu.be/NMudowLlbBM

So for different types of collision we need
to remember that e=1 for elastic collisions e=0
for inelastic collisions.