Answer:
The magnitude of the change in linear momentum of the ball is 6 kg-m/s.
Step-by-step explanation:
Given that,
Mass of the ball, m = 1 kg
Initial sped of the ball, u = 3 m/s
It strikes a wall and rebound, moving horizontally to the left at the same velocity of 3 m/s, v = -3 m/s
The magnitude of the change in linear momentum of the ball is given by :

So, the magnitude of the change in linear momentum of the ball is 6 kg-m/s.