1.3 know and use the relationship between average speed, distance moved and time: average speed = distance moved time taken

Formula:

average speed = distance moved
                             time taken

The reason why it is AVERAGE speed is because it does not take in to consideration stopping, going backwards or changing speeds.

Average speed is usually measured in m/s but can also be km/h, mph etc...

The formula can be rearranged:

distance moved = average speed x time taken

time taken = distance moved
                      average speed


Example:

1. If a car has travelled 3km in 1 hour, what is it's average speed. What units will you use?
2. If a bus travels at 20km/hr for 3 hours, how far will it have travelled. What units will you use?
3. If a lorry has travelled for 20 miles at 4 mph, how long did it take. What units will you use?

Answers:

1. 3 km/h
2. 60 km
3. 5 hours