Question

A car is traveling at vx = 30 m/s . The driver applies the brakes and the car decelerates at ax = -5.0 m/s2 . What is the stopping distance?

Answer 1

Answer:

90 m

Explanation:

We use an ecuation of uniformly accelerated motion, which allows us to find the distance traveled by the car from the moment that driver applies the brakes until it stops completely, that is, when its final speed is zero.

$v_{f}^2=v_{o}^2+2ad$

We isolate the variable d, knowing that the final speed $v_{f}$ is zero

$d=\frac{-v_{o}^2}{2a}\\d=\frac{-(30m/s)^2}{2(-5m/s^2)}=90 m$