Idea 7of 12Builds onEvery metre counts
How fast, on the path
How fast was she walking, over the whole trip?
Today you'll discover
- how 'how fast' comes from a distance and a time
- what 1.2 m/s means in metres and seconds
- why the whole-trip number has no direction
Think firstTwelve metres in ten seconds
Twelve metres walked in ten seconds. About how many metres each second?
Estimate first, then press Next. The bracket, the clock, then the division worked across the top.
Amara's walk drawn as legs, with the thin bracket above the figures labelled twelve metres walked and the boxed clock under the last figure reading ten seconds. Pressing Next adds a boxed line of working across the top of the picture: every metre walked divided by the time, twelve metres over ten seconds, equals 1.2 metres per second. The last step shows the dog's run and asks for its rate.
See the whole ideathe big idea and the key word, in one place
The big idea
Speed: distance divided by time. 1.2 metres each second, no direction.
See the patternTwelve metres over ten seconds is 1.2 metres per second. Over the whole trip, that is how fast she walked.
Key word
- speed
- distance divided by the time it took, in metres per second; a scalar
Ready to use it?
- Work out a speed from a distance and a time.