Grade 12:Physics Impulse, Momentum, Collision,Net strength,Resultant strength,Newton's 2nd law

Ball P of mass 0,16 kg, moving due east at a speed of 10 m∙s-1, collides caput-on with another ball Q of mass 0,2 kg, moving west at a speed of 15 m∙s-1. After the collision, ball P moves west at a speed of 5 m∙s-1, as shown in the diagram below. Ignore the effects of friction and the rotational effects of the balls.
4.1 Define the term momentum in words.
4.2 Calculate the:
4.2.1 Velocity of ball Q after the collision
4.2.2 Magnitude of the impulse on ball P during the collision