posted by Keith on .
a car is approaching a traffic light at 25m/s when it turns red. The driver takes 1 second to react and put his foot on the brake pedal, after which the car decelerates at 2m/s^2. find the distance needed for the car to come to stop after the light turns red
The distance that the car moves while decelerating is
X = Vo^2/(2a) = 625/4 = 156.3 feet
An additional distance of (25 m/s)*1 s = 25 m is travelled before the brakes are applied.
The sum of the two is the stopping distance