You should know the size of some everyday speeds, in metres per second. They are approximate values, because real speeds vary.
- Walking: about 1.5 m/s.
- Running: about 3 m/s.
- Cycling: about 6 m/s.
- A car: about 25 m/s.
- A train: about 50 m/s.
- An aeroplane: about 250 m/s.
- Sound in air: about 330 m/s.
- Wind: varies a lot. A breeze is about 5 m/s and a gale is over 20 m/s.
These values help you check whether an answer is sensible. Sound is faster than any of the vehicles in the list, and a person running is faster than a person walking. You can also use them in calculations. At 6 m/s, a cyclist covers 6 × 10 = 60 m in 10 s, using distance = speed × time.