Mass of each ball, m = 0.05 kg
Initial velocity of the ball = 6 m/s
Magnitude of the initial momentum of the ball, p1 = 0.05 x 6
= 0.3 kg m/s
After collision, the balls change their directions of motion without changing the magnitudes of their velocity.
Final momentum of each ball, pf = - 0.3 kg m/s
Impulse imparted to each ball = pf - pi = -0.3 -0.3 = -0.6 kg m/s
The negative sign indicates that the impulses imparted to the balls are opposite in direction.