A bus travels 400 m between two stops. It starts from rest and accelerates at 1.50 m/s^2 until it reaches a velocity of 9.00 m/s. The bus continues at this velocity and then decelerates at 2 m/s^2 until it comes to a halt. Find the total time required for the journey.

Answer 1

initially, v = at, so t = 9.00/1.50 = 6s
The distance covered is 1/2 at^2 = 27m
When decelerating, it takes 9/2 = 4.5s to stop
In that time, it covered 9*4.5 - 1/2 * 2 * 4.5^2 = 20.25m
So the distance covered at 9 m/s is 400-27-0.25 = 352.75
The total time is thus 6 + 352.75/9 + 4.5 = 49.69 s

Answer 2

i rechecked it and i got 44.33 something????