Fig shows the distance-time graph of three objects $A$, $B$ and $C$. Study the graph and answer the following questions :

$(a)$ Which of the three is travelling the fastest ?

$(b)$ Are all three ever at the same point on the road ?

$(c) $ How far has $C$ travelled when $B$ passes $A$ ?

$(d)$ How far has $B$ travelled by the time it passes $C$ ?

Distinguish between speed and velocity.

The speed-time graph for a car is shown is Fig.

$(a)$ Find how far does the car travel in the first $4,sec$. Shade the area on the graph that represents the distance travelled by the car during the period.

$(b)$ Which part of the graph represents uniform motion of the car ?

Under what condition(s) is the magnitude of average velocity of an object equal to its average speed ?

A driver of a car travelling at $52\, km\, h^{-1}$ applies the brakes and accelerates uniformly in the opposite direction. The car stops in $5\, s$. Another driver going at $3 \,km \,h^{-1}$ in another car applies his brakes slowly and stops in $10\, s$. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied ?