When people walk, run, or travel in a car their speed will change. They may speed up, slow down or pause for traffic. The speed at which a person can walk, run or cycle depends on many factors including:
Some typical values for speed in metres per second (m/s) include:
|Method of travel||Typical speed in m/s|
It is not only moving objects that have varying speed. The speed of the wind and the speed of sound also vary. A typical value for the speed of sound in air is about 330 m/s.
The average speed of a moving object can be calculated using the equation:
This is when:
A car travels 500 m in 50 s, then 1,500 m in 75 s. Calculate its average speed for the whole journey.
First calculate total distance travelled:
Then calculate total time taken:
To find v:
It is important in motion calculations to be able to easily convert between units, in particular between metres and kilometres, and seconds and hours.
1 metre is equal to 0.001 kilometres so to convert from metres to kilometres - divide by 1,000.
1 kilometre is equal to 1,000 metres so to convert from kilometres to metres - multiply by 1,000.
1 hour is equal to 3,600 seconds so to convert from hours to seconds - multiply by 3,600.
Convert the following into kilometres:
Convert the following into seconds:
Convert 1 m/s into km/h.