Mention the nature of motion of a body if its displacement$-$time graph is a straight line parallel to the time axis.

Can the distance travelled by a particle be zero when displacement is not zero?

$A$ piece of stone is thrown vertically upwards. It reaches its maximum height in $3 \ s$. If the acceleration of the stone is $9.8 \ m s^{-2}$ directed towards the ground,calculate the initial velocity of the stone with which it is thrown upwards. Find the maximum height attained by it.

If the displacement-time graph for a particle is parallel to the displacement axis,what is the velocity of the particle?

$A$ car is moving on a straight road with uniform acceleration. The following table gives the speed of the car at various instants of time.

Time $(s)$	$0$	$10$	$20$	$30$	$40$	$50$
Speed $(m s^{-1})$	$5$	$10$	$15$	$20$	$25$	$30$

$(i)$ Draw the speed-time graph representing the above set of observations.
$(ii)$ Find the acceleration of the car.

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.