Time and Transport

We've already looked at how to calculate speed, a rate between distance and time. 

 

We can also rearrange this formula to calculate distances and times as well. We just need to substitute in the values we know to find the one we don't know.

This is particularly useful if you're travelling because you can work out how long it will take you to get to your destination, how far away your destination is or how fast you have to travel to get to your destination by a certain time.

Let's look through some examples to see how.

 

Worked Examples

Question 1

If a bike can travel at an average speed of $22$22 kilometres per hour, how many hours will it take to travel between Canberra and Perth? Leave your answer to two decimal places.

Think: To do this question we first need to know how far in kilometres Canberra is from Perth. Then we will use the Speed-distance-time formula using the given value of the speed of the bike at $22$22km/h.

Do: Looking up on the table we see that Canberra is $3911$3911 km from Perth.

The formula is $Speed=\frac{Dis\tan ce}{Time}$Speed=DistanceTime​

Substituting in the values we know.  

$S$S	$=$=	$\frac{D}{T}$DT​
$22$22	$=$=	$\frac{3911}{T}$3911T​
$T$T	$=$=	$\frac{3911}{22}$391122​
$T$T	$=$=	$177.77$177.77

So it would take $177.77$177.77 hours to ride a bike from Canberra to Perth.  

 

Question 2 (video coming soon)

How long does it take to travel from Rome to Athens via bus then Athens to Madrid via bike, if a bus has an average speed of $95$95 km/h and a bike has an average speed of $30$30 km/h?

a) First, calculate your answer in hours, to two decimal places.

b) Now give your answer in hours and minutes, rounding the number of minutes to the nearest whole number.