What is the slope of the displacement $-$ time graph when the body has uniform motion?

$A$ truck running at $90 \text{ km h}^{-1}$ is brought to rest over a distance of $25 \text{ m}$. Calculate the retardation and time for which brakes are applied.

Distinguish between the terms distance and displacement.

There are $5$ houses on a street,$A, B, C, D$ and $E$. For all cases,assume that positions to the right are positive.
$(i)$ Draw a frame of reference with house $A$ as the origin and the positions of houses $B, C, D$ and $E$.
$(ii)$ You live in house $C$. What is your position relative to house $E$?
$(iii)$ What are the positions of houses $A$ and $D$,if house $B$ is taken as the reference point?

The distance-time graph below represents the motion of two buses $A$ and $B$.
$(i)$ What is the distance by which bus $B$ was ahead of bus $A$ initially?
$(ii)$ Do they ever meet each other? If so,when?
$(iii)$ What is the distance travelled by bus $A$ when it overtakes bus $B$?
$(iv)$ Find out the distance by which bus $A$ was ahead of bus $B$ at $t = 12 \ h$.
$(v)$ Which one of them is moving faster? Give reason.

The driver of a train $A$ travelling at a speed of $54\, km\, h^{-1}$ applies brakes and retards the train uniformly. The train stops in $5\, s$. Another train $B$ is travelling on the parallel track with a speed of $36\, km\, h^{-1}$. This driver also applies the brakes and the train retards uniformly. The train $B$ stops in $10\, s$. Plot the speed-time graph for both the trains on the same paper. Also,calculate the distance travelled by each train after the brakes were applied.