m/s and km/h
You learn to convert speed from metres per second to km per hour, and back.
How to work it out
- Remember: 1 metre per second is 3.6 km per hour.
- To get km per hour, multiply by 3.6.
- To get metres per second, divide by 3.6.
1
10
3,6
36
A worked example
10 m/s = ? km/h
- To get km per hour, multiply by 3.6.
- Work it out: 10 × 3.6 = 36.
- It is 36 km/h.
More examples
5 m/s = ? km/h
- To get km per hour, multiply by 3.6.
- Work it out in two parts: 5 × 3 = 15 and 5 × 0.6 = 3, together 18.
- It is 18 km/h.
72 km/h = ? m/s
- To get metres per second, divide by 3.6.
- Work it out: 72 ÷ 3.6 = 20.
- It is 20 m/s.
Try it yourself
18 km/h = ? m/s
15 m/s = ? km/h
Watch out
You multiply by 3.6 to get m/s: 36 km/h becomes 129.6 m/s.
Metres per second is a smaller number than km per hour. From km/h to m/s you divide.
Tips
- Learn the factor: 1 m/s is 3.6 km/h.
Why it works
An hour is 3,600 seconds. If you go 1 metre per second, in an hour you go 3,600 metres, and that is 3.6 km. That is why 1 m/s is exactly 3.6 km per hour.