Give an example of a body which covers a certain distance, but its displacement is zero

Answer the following questions

$(i)$ State the type of motion shown by a freely falling stone.

$(ii)$ When a stone is thrown vertically upwards its velocity is continuously decreased. Why ?

$(iii)$ Give an example of a motion in which average velocity is zero, but the average speed is not zero.

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

A motor bike running at $90 \,km h ^{-1}$, is slowed down to $54 \,km h^{-1}$ by the application of brakes, over a distance of $40\, m$. If the brakes are applied with the same force, calculate $(i)$ total time in which bike comes to rest $(ii)$ total distance travelled by bike.

Obtain a relation for the distance travelled by an object moving with a uniform acceleration in the interval between $4^{th}$ and $5^{th}$ seconds.