A car is driving at 25 m/s when the driver sees a sign indicating the speed limit has dropped to 15 m/s. It takes the car 4 seconds to slow down to the correct speed. What was the car's acceleration?

Question

Hint: A formula is needed.

Answer 1

Given

Vo = 25 m/s

V1 = 15 m/s

t = 4 seconds

Find:

Car's acceleration

Solution

V = a * t + Vo

15 = a * 4 + 25

a = 15-25/4 = -10/4 = -5/2 m/s^2