posted by Nick on .
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?
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.