A0.1 kg beach ball hit me moving forward at 4 m/s. after hitting me, it bounced back moving at the same speed
backward. what impulse acted on the beach ball?
a 40 n-s
b. 0.8 ns
c. 0.4 n-s
d. 80 n-s

0.4 N-s is the "impulse" acted on the "beach ball".

Option: C

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.