0.4 N-s is the "impulse" acted on the "beach ball".
Option: C
Step-by-step explanation:
Given that,
Mass of the "beach ball" is 0.1 kg.
The speed of the ball hits is 4 m/s.
We know that,
Whenever an object is collide with other object then an impulse is acted on object, this "impulse" causes "change in momentum".
Impulse acted on the beach ball is "mass" times "velocity".
Impulse = mass × velocity
Impulse = 0.1 × 4
Impulse = 0.4 kg m/s
Impulse = 0.4 N-s
Therefore, the "impulse" acted on the ball is 0.4 N-s.