A bus accelerates at 1.4 m/s2 from rest for 10 s. It then travels at constant speed for 26 s, after which it slows to a stop with an acceleration of magnitude 1.4 m/s2.

Question

A bus accelerates at 1.4 m/s2 from rest for 10 s. It then travels at constant speed for 26 s, after which it slows to a stop with an acceleration of magnitude 1.4 m/s2.
(a) What is the total distance that the bus travels?
(b) What was its average velocity?

bobpursley · Answer

distance=1/2*1.4*10^2 + 1.4*10*26+ gets you the distance till it starts to brake.
Now to deaccelerate from that velocity, it takes 10 sec (think on that).
distance braking= vi*t-1/2 a t^2 or
1.4*10*10-1/2 1.4 10^2=70m
add that to the above distance.

avg velocity= distance/total time=totaldistance/(10+26+10)