A remote-controlled toy car of mass 3.3 kg starts from rest at the origin at t = 0 and moves in the positive direction of an x axis. The net force on the car as a function of time is given by the figure. (a) What is the time rate of change of the momentum of the car at t = 3.0 s? (b) What is the momentum of the car at t = 3.0 s?