physics
posted by robert on .
A bus accelerates from rest at 1.5m/s^2 for 12s. It then travels for 25s after which it slows to a stop with an acceleration of magnitude 1.5m/s^2. (a) Find the total distance the bus travels And its average velocity of the trip.

A bus accelerates from rest at 1.5m/s^2 for 12s. It then travels for 25s after which it slows to a stop with an acceleration of magnitude 1.5m/s^2. (a) Find the total distance the bus travel snd its average velocity of the trip.

666 meters

x1 = (1/2)(1.5)(12^2) = 108 m
v1 = 1.5(12) = 18 m/s
x2 = 108 + 18(25) = 558 m
v2 = v1 = 18
x3 = 558 + 18 t  (1/2)1.5 t^2
v3 = 0
= 18  1.5 t
so t = 12 seconds to stop (of course)
then
x3 = 558 + 18(12)  (1/2)(1.5)(144)
= 558 + 216  108
= 666 meters 
a devil of a problem!