$A$ 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.

(N/A) $(i)$ The speed-time graph is plotted by taking time on the $x$-axis and speed on the $y$-axis. By plotting the given points $(0, 5), (10, 10), (20, 15), (30, 20), (40, 25), (50, 30)$, we get a straight line indicating uniform acceleration.
$(ii)$ The acceleration $(a)$ of the car is equal to the slope of the speed-time graph.
$a = \text{slope} = \frac{v_2 - v_1}{t_2 - t_1}$
Taking two points $(10, 10)$ and $(20, 15)$:
$a = \frac{15 - 10}{20 - 10} = \frac{5}{10} = 0.5 \ m s^{-2}$
Thus, the acceleration of the car is $0.5 \ m s^{-2}$.