Four cars $A$,$B$,$C$ and $D$ are moving on a levelled road. Their distance versus time graphs are shown in the figure. Choose the correct statement.

What can you conclude about the motion of a body depicted by the velocity-time graphs $(i)$,$(ii)$ and $(iii)$ given below?

State the type of motion represented by the given graph.

Account for the following:
$(a)$ What is the shape of the path of a body when it is in uniform motion?
$(b)$ Give one example of non-uniform motion.
$(c)$ Two cars $A$ and $B$ have their $x-t$ graph as shown in the figure. Which has greater velocity?
$(d)$ What is the quantity which is measured by the area occupied below the velocity-time graph?
$(e)$ $A$ body is moving with a velocity of $10 \, m/s$. If the motion is uniform,what will be the velocity after $10 \, s$?

Ali,while driving to school,computes the average speed for his trip to be $20 \, km \, h^{-1}$. On his return trip along the same route,there is less traffic and the average speed is $30 \, km \, h^{-1}$. What is the average speed for Ali's entire trip?

$A$ body thrown in the vertically upward direction rises up to a height $h$ and comes back to the position of its start. Calculate: $(a)$ the total distance travelled by the body and $(b)$ the displacement of the body. Under what condition will the magnitude of the displacement be equal to the distance travelled by an object?