A car is traveling at 28 m/s when the driver spots a large pothole in the road a distance 37 m ahead. She immediately applies her brakes. If her acceleration is -7.8 m/s2, does she manage to stop before reaching the pothole? What is this stopping distance?

1 answer

The time required to stop is
T = Vo/|a| = 28/7.8 = 3.59 seconds.
The average speed during that time is Vo/2 = 14 m/s. The distance travelled while decelerating is
Vav*T = (Vo/2)*T = 14 m/s*3.59s = 50.26 m

She cannot stop in time to miss the pothole.