In a collision, the ratio of the magnitudes of the initial and final relative velocities is called the coefficient of restitution and denoted by the symbol e, If the magnitude of the final relativ...In a collision, the ratio of the magnitudes of the initial and final relative velocities is called the coefficient of restitution and denoted by the symbol e, If the magnitude of the final relative velocity is less than the magnitude of the initial relative velocity, e<1, then the change in kinetic energy is negative. If the magnitude of the final relative velocity is greater than the magnitude of the initial relative velocity, e>1, then the change in kinetic energy is positive.
