Class 11 NEET Physics Work, Energy and Power Questions

Coefficient of restitution or resilience of two bodies is defined as the constant ratio of relative velocity after impact to the relative velocity of the bodies before impact when the two bodies collide head on. Their velocities are in the opposite directions.
Thus

v1−v2

u1−u2

= constant =−e
The constant e is known as coefficient of restitution or resilience of two bodies. For a perfectly elastic collision, e=1 and for a perfectly inelastic collision, e=0. Thus 0≤e≤1