Question

A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds:

(a) What is its average speed?
(b) How far does it travel in 1 second?
(c) How far does it travel in 6 seconds?
(d) How long does it take to travel 240 m?

Answer 1

(a) We have:
Distance (d) = 150 m
Time (t) = 5s
So, we can calculate average the speed as:
$\mathrm{Average}\mathrm{speed}=\frac{\mathrm{Total}\mathrm{distance}\mathrm{travelled}}{\mathrm{Time}}$
Average speed for the entire journey:
$$\begin{gathered} =\frac{150}{5} \\ =\boxed{30\mathrm{m}/\mathrm{s}} \end{gathered}$$

(b) We have to calculate the distance travelled in 1s.
Distance = (Speed) (Time)
Distance travelled in one second:
=(30) (1) m
$=\boxed{30\mathrm{m}}$

(c) We have to calculate the distance travelled in 6 s.
Distance = (Speed) (Time)
Distance travelled in one second:
= (30) (6) m
$=\boxed{180\mathrm{m}}$

(d) We have:
Distance (d) = 240 m
Speed (v) = 30 m/s
We can find the time as:
$$\begin{gathered} \mathrm{Time}=\frac{\mathrm{Distance}\mathrm{travelled}}{\mathrm{Speed}} \\ So, \\ t\mathit{=}\frac{240}{30}\mathrm{s} \\ =\boxed{8\mathrm{s}} \end{gathered}$$