If a bus you are riding is traveling at a constant speed and then stops abruptly, you feel "thrown” forward. Which of the following is true at the instant the bus begins to stop? Suppose the seat is frictionless and that you are not wearing a seatbelt.

Select one:

1. You slide forward on the frictionless seat at the same velocity that the bus was traveling prior to the stop.

2. A force is throwing you forward.

3. You are accelerating (remember, there is acceleration when velocities are changing).