Identify what the graphs shown below indicate.

$A$ motorcyclist drives from $A$ to $B$ with a uniform speed of $30\, km\, h^{-1}$ and returns back with a speed of $20\, km\, h^{-1}$. Find its average speed (in $km\, h^{-1}$).

$A$ cyclist travels a distance of $4\, km$ from $P$ to $Q$ and then moves a distance of $3\, km$ at a right angle to $PQ$. Find his resultant displacement graphically.

The distance-time graph of two trains is given below. The trains start simultaneously in the same direction.
$(i)$ How much ahead of $A$ is $B$ when the motion starts?
$(ii)$ What is the speed of $B$?
$(iii)$ When and where will $A$ catch $B$?
$(iv)$ What is the difference between the speeds of $A$ and $B$?
$(v)$ Is the speed of either train uniform or non-uniform? Justify your answer.

State whether the following statement is true or false:
In one-dimensional motion,the average velocity and the instantaneous velocity are unequal.

Two graphs for the motion of objects moving along a straight line are shown. State how the speed is changing with time in both cases.