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3.03 Speed and fuel consumption

Lesson

Speed

Measurement of speed is a rate many people use daily when driving their car. Speed is the ratio between distance and time.

In Australia and many other countries the standard is kilometres per hour (km/h).

Formulae for speed, distance and time

To calculate speed, we can use the formula:    $\text{Speed}=\frac{\text{Distance}}{\text{Time}}$Speed=DistanceTime

To find time we use:    $\text{Time}=\frac{\text{Distance}}{\text{Speed}}$Time=DistanceSpeed

Or to calculate distance we use:    $\text{Distance}=\text{Speed}\times\text{Time}$Distance=Speed×Time

 

Practice questions

Question 1

A dog travels $42$42 km in $1.4$1.4 hours.

  1. At what speed is it travelling?

Question 2

What is the time required for a car to travel $170$170 kilometres at a speed of $10$10 kilometres per hour?

Question 3

What is the distance travelled by a car if it travels at $60$60 kilometres per hour for $9$9 hours?

Question 4

Homer is driving $700$700 kilometres to visit their family. The car has a fuel economy of $5$5 L/$100$100 km. How many litres of fuel will Homer require to make this trip?

 

Outcomes

1.1.17

convert units of rates occurring in practical situations to solve problems. For example, 1 tablespoon (tbsp) = 4 teaspoons (tsp) or 1 tbsp = 20 ml (Australia) or 15 ml (US and UK)

1.1.18

use rates to make comparisons

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