An electric vehicle starts from rest and accelerates at a rate of 3.0 m/s2 in a straight line until it reaches a speed of 26 m/s. The vehicle then slows at a constant rate of 1.0 m/s2 until it stops.

a)How much time elapses from start to stop?

b)How far does the vehicle travel from start to stop?

2 answers

a) Add up the times it takes to accelerate and decelerate.
The time required to accelerate is
(26 m/s)/3 m/s^2 = 8.67 s
The time required to decelerate from 26 m/s^2 at a constant rate of -1 m/s^2 is 26 s.

b) Add up the distances covered while accelerating and decelerating. Each equals the average velocity (13 m/s) times the time interval.
Thank you.