The displacement-time graph of a body is parallel to the time axis. What will you infer about the velocity of the body?

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

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

Draw the speed-time graph by choosing a convenient scale. Determine from it:
$(i)$ The acceleration of the truck.
$(ii)$ The distance travelled by the truck in $50$ seconds.

For the motion on a straight line path with constant acceleration,the ratio of the magnitude of the displacement to the distance covered is

The velocity$-$time graph of a body has a negative slope. The body is undergoing

Define acceleration. State a relationship connecting $u, v, a$ and $t$ for an accelerated motion. Give an example of a motion in which acceleration is uniform.

The velocity-time graph of a truck is plotted below.
$(a)$ Calculate the magnitude of displacement of the truck in $15$ seconds.
$(b)$ During which part of the journey was the truck decelerating?
$(c)$ Calculate the magnitude of average velocity of the truck.