Metre per second
From Wikipedia, the free encyclopedia
Metre per second (U.S. spelling: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector quantity which specifies both magnitude and a specific direction), defined by distance in metres divided by time in seconds.
The proper official SI symbol and abbreviation is m·s−1, or equivalently, m/s, but it is sometimes colloquially seen the quantity incorrectly abbreviated by the three character mnemonic mps in some U.S. coverage.
Astronomical measurements sometimes list velocities in terms of kilometres per second, where a kilometre per second (Symbol: km/s)is equivalent to 1 000 metres per second. Some U.S. literature (normally science fiction or magazines) sometimes incorrectly abbreviates this multiple quantity as kps.
After knowing its formal definition, in order to know quantitatively how much 1 metre per second is, it is possible to think that the average person makes steps of approximately 1 metre each second, so his velocity is 1 step each second, that would be about 1 metre per second. In other words, 1 metre per second is close to the speed of an average person walking. Representing a speed with such a unit expresses how many times something is moving faster than a person walking.
[edit] Conversions
1 metre per second is equivalent to:
- ≈ 3.2808 feet per second (approximately)
- ≈ 2.2369 miles per hour (approximately)
- = 3.6 km·h−1 (exactly)
1 foot per second = 0.3048 m·s−1 (exactly)
1 mile per hour ≈ 0.4471 m·s−1 (approximately)
1 km·h-1 ≈ 0.2778 m·s−1 (approximately)
1 kilometre per second is equivalent to:
- ≈ 0.6213 miles per second (approximately)
- ≈ 2,237 miles per hour (approximately)
[edit] Remark
Although m·s−1 is considered as a derived unit, it could be viewed as more fundamental than the metre, since the latter is defined through the speed of light in the vacuum, taken to be exactly 299 792 458 m·s−1 by definition, which then gives the metre using the definition of one second.
