Miles per hour

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Automobile speedometer, indicating speed in miles per hour on the outer track and kilometres per hour on the inner track

Miles per hour (abbreviated mph, MPH or mi/h) is an imperial and United States customary unit of speed expressing the number of statute miles covered in one hour. While kilometres per hour is more commonly used worldwide, miles per hour remains the standard unit used for speed limits in some countries, and to express speeds generally, in many countries throughout the world.

These include roads in the United Kingdom,[1] the United States,[2] and UK and US territories; American Samoa,[3] the Bahamas,[4] Belize,[5] British Virgin Islands,[6] the Cayman Islands,[7] Dominica,[8] the Falkland Islands,[9] Grenada,[10] Guam,[11] Burma,[12] The N. Mariana Islands,[13] Samoa,[14] St. Lucia,[15] St. Vincent & The Grenadines,[16] St. Helena,[17] St. Kitts & Nevis,[18] Turks & Caicos Islands,[19] the U.S. Virgin Islands,[20][21] Antigua & Barbuda (although km are used for distance),[22] and Puerto Rico (same as former).[22]

Miles per hour are also used in the Canadian rail system.[23] In some countries it may be used to express the speed of delivery of a ball in sporting events such as cricket, tennis and baseball.

Road traffic speeds in other countries are quoted in kilometres per hour. Occasionally, however, both systems are used: for example, in Ireland, a judge considered a speeding case by examining speeds in both kilometres per hour and miles per hour. The judge was quoted as saying the speed seemed "very excessive" at 180 km/h but did not look "as bad" at 112 mph; a reduced fine was still imposed on the speeding driver.[24]

Nautical and aeronautical applications, however, favour the knot as a common unit of speed: one knot is one nautical mile per hour.

Conversions[edit]

1 mph = 0.4470m/s (exactly)
= 1.609344 km/h (exactly)
≈ 1.467 ft/s (approximately)
0.868976 kn
Conversions between common units of speed
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.)

1 Mph = 0.000277778 Mps (Miles Per Second)

Example: Apollo 11 attained speeds of 25,000 Mph, which converts to about 7 Mps. If Apollo 11 were to travel at 25,000 Mph from New York to Los Angeles it would reach Los Angeles in under 6 minutes.

See also[edit]

References[edit]

  1. ^ Speed limit signs (UK) Department for Transport. Retrieved 14 September 2011
  2. ^ "Modern Living: Think Metric". Time Magazine. 9 June 1975. Retrieved 15 June 2010. "Meanwhile, the metricization of America is already taking place. Individual federal agencies, school systems, states and industries, as well as radio announcers, supermarkets, beverage bottlers and ballpark scoreboards, are hastening the everyday use of meters, liters and grams. ...a road sign outside Fergus Falls reads, ST. CLOUD 100 MILES OR 161 KILOMETERS. Other signs note that 55 m.p.h. equals 88 kilometers per hour." 
  3. ^ http://www.samoanews.com/?q=node/76715
  4. ^ http://www.thenassauguardian.com/index.php?option=com_content&view=article&id=40272:major-hurricanes-to-hit-the-bahamas&catid=84:hurricane
  5. ^ http://amandala.com.bz/news/?p=263765&upm_export=pdf
  6. ^ http://www.bvibeacon.com/120105/hurricane120105.html
  7. ^ http://www.compasscayman.com/caycompass/2013/06/06/Driver-exceeded-critical-speed-of-91-mph,-jury-hears/
  8. ^ http://dominicanewsonline.com/news/homepage/news/general/ophelia-less-organised-but-still-a-strong-tropical-storm/
  9. ^ http://www.penguin-news.com/index.php/columns/item/318-an-islanders-offerings-from-essex-by-james-marsh
  10. ^ http://www.grenadabroadcast.com/news/other/15927-troublesome-figures
  11. ^ http://www.guampdn.com/guampublishing/special-sections/mailahalom08/typhoon.shtml
  12. ^ File:Naypyitaw Tollbooth.jpg
  13. ^ [1][dead link]
  14. ^ http://www.samoaobserver.ws/other/community/3229-gale-warning-issued-apia-town-drowns
  15. ^ http://www.thevoiceslu.com/local_news/2008/may/24_05_08/Retrial_goes_ahead.htm
  16. ^ http://www.iwnsvg.com/2010/10/31/st-vincent-appeals-for-aid-as-tomas-leaves-millions-and-millions-in-damage/
  17. ^ http://sthelenaonline.org/2012/10/23/paraglider-pilot-flies-over-st-helena/
  18. ^ http://www.thestkittsnevisobserver.com/2012/08/17/ts-isaac.html
  19. ^ http://suntci.com/police-urging-motorists-to-slow-down-p183-106.htm
  20. ^ http://virginislandsdailynews.com/cops-teen-was-driving-75-mph-in-city-rollover-crash-1.1171653?cache=03D163D03D163Dp%3A%2Fhe3D03Dn63Freporti3D19.11145issed-1%3FparentPage%3D2.1244
  21. ^ http://virginislandsdailynews.com/news/weather-to-begin-clearing-up-today-as-isaac-leaves-area-1.1363173
  22. ^ a b https://en.wikipedia.org/w/index.php?title=Miles_per_hour&action=edit
  23. ^ "A. Classes of Track". Rules Respecting Track Safety. Transport Canada. 3 November 2008. Archived from the original on 2012-08-25.  Archived 25 August 2012.
  24. ^ "Another Metric System Fault". The New York Times. Associated Press. 1 November 2007. Retrieved 1 November 2010.