Question

3. Ryan is driving a car at 22 m/s when he sees a child standing in the road. He takes 0.83 s to

react, then steps on the brakes and slows down at 7.11 m/s². How far does the car travel
before it stops?

Answer 1

S1 = V0 t - 1/2 a t^2 to stop moving car

t = 22m/s / 7.11 m/s^2 = 3.09 sec to decelerate moving car

S1 = 22 * 3.09 - 1/2 ^ 7.11 * 3.09^2 = 34.0 m to decelerate car

22 m/s * .83 s = 18.3 m distance traveled due to reaction time

S = (34.0 + 18.3) m = 52.3 m or about 172 ft