Aball (mass 0.40 kg) is initially moving to the left at 30 m/s. after hitting the wall, the ball is moving to the right at 20 m/s. what is the impulse of the net force on the ball during its collision with the wall?

Impulse, J = 20 m/s  

Explanation:

Given that,

Mass of the ball, m = 0.4 kg

Initial speed of the ball, u = -30 m/s (left)    

Final speed of the ball after hitting, v = 20 m/s (right)

Let J is the impulse of the net force on the ball during its collision with the wall. The change in momentum of an object is equal to the impulse imparted to it. It is given by :

J = -20 m/s

So, the magnitude of impulse of the net force on the ball during its collision with the wall is 20 m/s.

33: i think it’s b

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle