A ball of mass m moving with a speed u undergoes a head - on elastic collision with a ball of mass nm initially at rest. The fraction of the incident energy transferred to the heavier ball is

Let the velocities of the two balls, after collision be v1 and v2 is the direction of u which is taken as positive.mu=mv1+nmv2,e=1 v2−v1=u,v2=2un+1Fractional energy transferred =K.E.of ball of mass nmincident energy =12nm×2un+1212mu2=4n(n+1)2