A soccer ball (mass = 0.43 kg)is moving at a speed of 20 m/s when it is kicked with a force of 300 N resulting in it going in the opposite direction with the same speed as before.What is the magnitude of the impulse delivered to the ball?
A)0,because the before and after momenta cancel each other.
B)8.6 kg·m/s
C)17 kg·m/s
D)2 600 kg·m/s

Question

Quizplus · Accepted Answer

The impulse delivered to an object is equal to the change in its momentum.

Initial momentum = m*v = 0.43 kg * 20 m/s = 8.6 kg*m/s (to the right)
Final momentum = -m*v = -0.43 kg * 20 m/s = -8.6 kg*m/s (to the left)

Change in momentum = Final momentum - Initial momentum
= (-8.6 kg*m/s) - (8.6 kg*m/s)
= -17 kg*m/s

Since the ball was kicked in the opposite direction, the impulse delivered to it would be in the opposite direction as well. Therefore, the magnitude of the impulse would be |-17 kg*m/s| = 17 kg*m/s.

Thus, the correct answer is C.

A Soccer Ball (Mass = 0