Let the two balls A and B moving in opposite directions collide and rebound with same speed.
Initial momentum of the ball A = 0.05 × (6) = 0.3 kg m s ‌–1
Final momentum of the ball A = 0.05(–6) = –0.3 kg m s‌–1
Impulse imparted to ball A = change in momentum of ball
A= final momentum - initial momentum =−0.3−0.3=−0.6 kg m s−1
Initial momentum of the ball B=0.05×(−6)=−0.3kg m s−1
Final momentum of the ball B=0.05×(6)=0.3kg m s−1
Impulse imparted due to B=0.3−(−0.3)=0.6 kg m s−1
Impulse on each ball is 0.6 kg m s−1 in magnitude but these two impulses are opposite in direction.