You are driving through town at 13 m/s when suddenly a car backs

out of a driveway in front of you. You apply the brakes and begin

decelerating at 3.2 m/s.

How much time does it take you to stop?

t = 4.06 s

Explanation:

Formula

a = v₂ - v₁ / t

a = - 3.2 m/s²

v₂ = 0 because the car will stop

v₁ = 13 m/s

then we clear time from the equation

t = v₂ - v₁ / a

and we substitute the values

t = 0 - 13 / - 3.2 = - 13/-3.2 = 4.06 s