Answer:
24.325 kg m/s
Step-by-step explanation:
Initial momentum, pi = 18 kg m/s
F = < -4, 12, 0>
t = 0.5 s
Let the final momentum is pf.
The magnitude of force is

According to the Newton's second law, the rate of change of momentum is equal to the force.


pf - 18 = 6.325
pf = 24.325 kg m/s
Thus, the momentum of body after 0.5 s is 24.325 kg m/s.