Study the speed$-$time graph of a body given below and answer the following questions

$(i)$ What type of motion is represented by $OA, AB$ and $BC$ ?

$(ii)$ Find positive and negative accelerations of the body.

$(iii)$ Find the distance travelled by the body from $A$ to $B$.

A body moves with a velocity of $2\, m s ^{-1}$ for $5\, s$, then its velocity increases uniformly to $10\, m s ^{-1}$ in next $5\, s.$ Thereafter, its velocity begins to decrease at a uniform rate until it comes to rest after $5\, s$.

$(i)$ Plot a velocity-time graph for the motion of the body.

$(ii)$ From the graph, find the total distance covered by the body after $2\, s$ and $12\, s$.

State the type of motion represented by the given graph.

$(a)$ A car moving with uniform velocity $'u^{\prime}$ and uniform acceleration $'a^{\prime}$ covers a distance $'S^{\prime}$ in time $'t^{\prime}$. Draw its velocity $-$ time graph and derive an expression relating all the given physical quantities.

$(b)$ A boy revolves a stone tied to a string $0.7 \,m$ long. Find the distance and displacement covered by the stone in completing two revolutions from starting point.

$(a)$ Define uniform circular motion.

$(b)$ Is the uniform circular motion an accelerated motion? Give reasons for your answer.