Kilometres Per Hour Information
The kilometre per hour (American English: kilometer per hour) is a unit of speed or velocity, expressing the number of kilometres traveled in one hour. The unit symbol is km/h or km·h−1.
Worldwide, the km/h is the most commonly used speed unit on road signs and car speedometers. Along with the kW·h, km/h is the most commonly used metric unit based on the hour, the latter being a unit for time accepted for use with the International System of Units by the International Bureau of Weights and Measures (BIPM).[1]
In Australian and North American slang and military usage, km/h is commonly pronounced, and sometimes even written, as klicks or kays (K's), although these may also be used to refer to kilometres.[citation needed]
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Use of kph
The colloquial abbreviations "kph" and "kmph" are sometimes also used in English-speaking countries, in analogy to miles per hour (mph), even though the official recommendation from the BIPM is to use km/h. The symbol (as opposed to abbreviation) is in near-universal use elsewhere, even though the letters "km" and "h" do not always correspond to "kilometres" or "hours" in the language concerned.
Irish speed restriction sign showing km/hThe following are translations of the text "kilometres per hour" where either "km" or "h" do not appear in the text.[2]
- Italian: Chilometri all'ora
- Dutch: kilometer per uur
- German: Kilometer pro Stunde
- Greek: χιλιόμετρα ανά ώρα
- Portuguese: quilómetros por hora / quilômetro por hora
- Bulgarian Километър в час
- Russian: Километр в час
In all cases, EU directives require the use of "km/h" in official documents in these languages.
Conversions
- 3.6 km/h ≡ 1 m/s, the SI unit of speed, metre per second
- 1 km/h ≈ 0.277 78 m/s
- 1 km/h ≈ 0.621 37 mph ≈ 0.911 34 feet per second
- 1 knot ≡ 1.852 km/h (exactly)
- 1 mile per hour ≡ 1.609344 km/h (~1.61 km/h)[3]
| m/s | km/h | mph | knot | ft/s | |
|---|---|---|---|---|---|
| 1 m/s = | 1 | 3.6 | 2.236936 | 1.943844 | 3.280840 |
| 1 km/h = | 0.277778 | 1 | 0.621371 | 0.539957 | 0.911344 |
| 1 mph = | 0.44704 | 1.609344 | 1 | 0.868976 | 1.466667 |
| 1 knot = | 0.514444 | 1.852 | 1.150779 | 1 | 1.687810 |
| 1 ft/s = | 0.3048 | 1.09728 | 0.681818 | 0.592484 | 1 |
(Values in bold face are exact.)
See also
References
- ^ BIPM brochure (SI reference)
- ^ "Online Translation- Offering hundreds of dictionaries and translation in more than 800 language pairs". Babylon. http://translation.babylon.com/. Retrieved 2011-01-24.
- ^ 1 yard ≡ 0.9144 m and 1 mile = 1760 yards thus 1 mile = 1760 × 0.9144 ÷ 1000 km
Categories: Units of velocity | Non-SI metric units
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