collision, elastic and inelastic In all collisions, the total momentum, linear as well as angular, of the particles before and after the collision remains the same (principle of conservation of linear and angular momentum). In elastic collision, in addition, the kinetic energy is also conserved.
In inelastic collision the kinetic energy is not conserved. The lost kinetic energy appears as heat or some other form of energy.
In elastic collision in one dimension, between two particles of masses m1 and m2, moving with velocities v1 and v2 ,we can write two equations. The first equation is wriiten, equating the total momentum of the particles before and after the collision; and the second equating the kinetic energy of the particles before and after the collision. The final velocities, v1f and v2f, of the particles after the collision can be found by solving the two equations simultaneously.