$A$ train is travelling at a speed of $90\, km \,h^{-1}$. Brakes are applied so as to produce a uniform acceleration of $-0.5\, m s^{-2}$. Find how far (in $m$) the train will go before it is brought to rest.

$A$ bus starting from rest moves with a uniform acceleration of $0.1\, m s^{-2}$ for $2\, min$. Find $(a)$ the speed acquired,$(b)$ the distance travelled.

The speed-time graph for a car is shown in the figure.
$(a)$ Find how far the car travels in the first $4 \, s$. Shade the area on the graph that represents the distance travelled by the car during this period.
$(b)$ Which part of the graph represents the uniform motion of the car?

During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light, that is, $3 \times 10^{8} \, m \, s^{-1}$.

What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis?

Distinguish between speed and velocity.