Four speed$-$time graphs are shown below

Which graph represents the following case ?

$(i)$ A ball thrown vertically upwards and returning to the hand of the thrower ?

$(ii)$ A body decelerating to a constant speed and then accelerating.

$(a)$ Derive graphically the equation for velocity$-$time relation.

$(b)$ Name the device used to measure distance travelled by a vehicle.

$(c)$ Can displacement of a moving object be zero ? Give reason.

The velocity-time graph of cars $A$ and $B$ which start from the same place and move along a straight road in the same direction is shown below

Calculate :

$(a)$ the acceleration of car $B$ between $2 \,s$ and $4\, s$.

$(b)$ the time at which both the cars have the same velocity.

$(c)$ the distance travelled by the two cars $A$ and $B$ in $8\, s$

$(d)$ Which of the two cars is ahead after $8\, s$ and by how much ?

$(a)$ Define uniform circular motion.

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

State the type of motion represented by the given graph.