A (60.0 kg) person is walking at a speed of 2.0 m/sec. A bully comes up from behind and pushes on this person for 0.2 sec with a force of 200 N.

a. What is the person's initial momentum?

a. 120 kg·m/s
b. 60 N·s
c. 240 N·s
d. 30 kg·m/s