Which of the following scenarios involves a change in momentum of 7,700kg • m/s?
A.) an object with a mass of 7,700 kg is at rest on top of a hill
B.) two objects with a total mass of 3,600 kg move together with a constant velocity of 20 m/s
C.) a 1,540 kg car decreases its velocity from 20 m/s to 15 m/s
D.) a 2,200 kg truck increases its velocity from 9 m/s to 11 m/s