A car is traveling with constant velocity along a highway. The driver notices he is late for work, so he stomps down on the gas pedal and the car begins to speed up. The car has just achieved double its initial velocity when the driver spots a police officer behind him and applies the brakes. The car then slows down, coming to rest at a stoplight ahead. Draw a complete motion diagram for this situation.
Part A
The car’s motion can be divided into three different stages: its motion before the driver realizes he’s late, its motion after the driver hits the gas (but before he sees the police car), and its motion after the driver sees the police car. Which of the following simplifying assumptions is it reasonable to make in this problem?
A. During each of the three different stages of its motion, the car is moving with constant acceleration.
B. During each of the three different stages of its motion, the car is moving with constant velocity.
C. The highway is straight (i.e., there are no curves).
D. The highway is level (i.e., there are no hills or valleys).