(C) The mass speeds up with constant acceleration.
(D) The mass oscillates, never getting farther than 5 cm from x = 0.
(E) The mass oscillates, never getting farther than 10 cm from x = 0.
4 . Two identical balls of mass m = 1.0 kg are moving towards each other, as shown above. What is the
initial kinetic energy of the system consisting of the two balls?
(A) 0 joules
(B) 1 joules
(C) 12 joules
(D) 18 joules
(E) 36 joules
Free Response:
5 . A 1500-kg car moves north according to the velocity–time graph shown.
(a) Determine the change in the car’s kinetic energy during the first 7 s.
(b) To determine how far the car traveled in these 7 s, the three basic kinematics equations can not be
used. Explain why not.
(c) Use the velocity–time graph to estimate the distance the car traveled in 7 s.
(d) What was the net work done on the car in these 7 s?
(e) Determine the average power necessary for the car to perform this motion.
