{{short description|SI derived unit of speed and velocity}} {{redirect|m/s|other uses}} {{infobox unit | name = metre per second | image = | caption = | standard = [[International System of Units|SI]] | quantity = [[speed]] | symbol = m/s | units1 = [[Kilometres per hour|km/h]] | inunits1 = 3.6 | units2 = [[Miles per hour|mph]] | inunits2 = 2.2369 | units3 = [[Knot (unit)|kn]] | inunits3 = 1.9438 | units4 = [[Foot per second|ft/s]] | inunits4 = 3.2808 }} The '''metre per second''' ([[American and British English spelling differences|alternatively]] spelled '''meter per second''') is the unit of both [[speed]] (a [[scalar (physics)|scalar quantity]]) and [[velocity]] (a [[Vector (mathematics and physics)|vector quantity]], which has direction and magnitude) in the [[International System of Units]] (SI), equal to the speed of a body covering a [[distance]] of one [[metre]] in a time of one [[second]]. As the base unit for speed in the SI, it is commonly used in physics, mechanics, and engineering contexts. It represents both scalar speed and vector velocity, depending on context. According to the definition of metre,<ref name="nist-definitions">{{cite web |date=29 May 2019 |title=Definitions of the SI base units |url=https://physics.nist.gov/cuu/Units/current.html |access-date=8 February 2022 |website=physics.nist.gov}}</ref> {{val|1|u=m/s}} is exactly {{sfrac|1|{{val|299792458}}}} of the [[speed of light]]. [[File:Velocity vs Time Graph.png|alt=Velocity vs Time Graph|thumb|A velocity(In vector metres per second) versus time chart. It shows how the unit metre per second is often used in scientific and educational occasions.]] The [[International System of Units|SI unit]] symbols are '''m/s''', '''m·s<sup>−1</sup>''', '''m s<sup>−1</sup>''', or '''{{sfrac|m|s}}'''.<ref>{{cite web |url=https://www.bipm.org/en/publications/si-brochure/section5-1.html |title=SI brochure, Section 5.1 |access-date=2018-06-08 |archive-date=2019-03-21 |archive-url=https://web.archive.org/web/20190321011313/https://www.bipm.org/en/publications/si-brochure/section5-1.html |url-status=dead }}</ref>
== Conversions == {{val|1|u=m/s}} is equivalent to: : = 3.6 [[kilometres per hour|km/h]] (exactly)<ref>{{cite book |url=https://books.google.com/books?id=Zc14AAAAQBAJ |title=South African Automotive Light Vehicle Level 3 |last=CDX Automotive |publisher=Jones & Bartlett Learning |year=2013 |isbn=978-1449697853 |pages=478 }}</ref> : ≈ 3.2808 [[feet per second]] (approximately)<ref>{{cite book |title=EXERGY: Energy, Environment and Sustainable Development |last1=Dinçer |first1=İbrahim |last2=Rosen |first2=Marc A. |publisher=Elsevier |year=2007 |isbn=9780080531359 |location=Amsterdam |pages=444 |oclc=228148217 }}</ref> : ≈ 2.2369 [[miles per hour]] (approximately)<ref>{{cite book |title=Vehicle Dynamics: Theory and Application |last=Jazar |first=Reza N. |publisher=Springer |year=2017 |isbn=9783319534411 |edition=3rd |location=Cham, Switzerland |pages=957 |oclc=988750637 }}</ref> : ≈ 1.9438 [[knot (unit)|knots]] (approximately)<ref>{{cite book |title=Introduction to Avionics Systems |last=Collinson |first=R.P.G. |publisher=Springer Science & Business Media |year=2013 |isbn=9781441974662 |edition=2nd |location=Boston |pages=16 |oclc=861706692 }}</ref>
1 [[feet per second|foot per second]] = {{val|0.3048|u=m/s}} (exactly)<ref>{{cite book |url=https://books.google.com/books?id=RsQaCgAAQBAJ |title=Mechanics of Fluids, SI Edition |last1=Potter |first1=Merle C |last2=Wiggert |first2=David C |last3=Ramadan |first3=Bassem H. |publisher=Cengage Learning |year=2016 |isbn=978-1305887701 |edition=5th |pages=722 }}</ref>
1 [[miles per hour|mile per hour]] = {{val|0.44704|u=m/s}} (exactly)<ref>{{cite book |title=Mechanics for Engineers: Statics |last1=Das |first1=Braja M. |last2=Kassimali |first2=Aslam |last3=Sami |first3=Sedat |publisher=J. Ross Publishing |year=2010 |isbn=9781604270297 |location=Ft. Lauderdale, FL |pages=556 |oclc=419827343 }}</ref>
1 [[kilometres per hour|km/h]] = 0.27777.... m/s (exactly)<ref>{{cite book |title=Fundamentals of medium/heavy duty diesel engines |last=Wright |first=Gus |publisher=Jones & Bartlett Publishers |year=2015 |isbn=9781284067057 |location=Burlington, Massachusetts |pages=1349 |oclc=927104266 }}</ref>
== History and Standardization == The metre per second became the official SI derived unit for both speed and velocity with the establishment of the International System of Units (SI) in 1960 by the '''[[General Conference on Weights and Measures|General Conference on Weights and Measures (CGPM)]]'''.<ref>{{cite web |title=SI Brochure - BIPM |url=https://www.bipm.org/en/publications/si-brochure |archive-url=https://web.archive.org/web/20250624073651/https://www.bipm.org/en/publications/si-brochure |archive-date=2025-06-24 |access-date=2025-07-04 |website=BIPM |language=en-US }}</ref> Prior to this, various units such as '''[[Foot per second|feet per second]]''', '''[[miles per hour]]''', and '''[[Knot (unit)|knots]]''' were more commonly used, depending on the region and application.
The unit derives from the SI base units of '''metre (length)''' and '''second (time)''', both of which were defined more precisely in the 20th century. The '''metre''' was originally based on the dimensions of the Earth, but is now defined by the distance light travels in vacuum in 1/{{val|299,792,458}} of a second. The '''second''' is defined using the vibration frequency of caesium atoms ({{val|9,192,631,770}} oscillations per second).<ref>{{cite web |title=Second {{!}} COSMOS |url=https://astronomy.swin.edu.au/cosmos/S/Second |access-date=2025-07-04 |website=astronomy.swin.edu.au }}</ref> Because of its accuracy, simplicity and preciseness, this unit is adopted as the official unit of speed and velocity and is almost always used as the unit of speed and velocity in scientific occasions.
== Relation to other measures == The '''benz''', named in honour of [[Karl Benz]], has been proposed as a name for one metre per second.<ref name="Klein2011"/> Although it has seen some support as a practical unit,<ref name="Heijungs2005"/> primarily from German sources,<ref name="Klein2011"/> it was rejected as the SI unit of velocity<ref name="Cardarelli2004"/> and has not seen widespread use or acceptance.<ref name="Dresner1974"/>
The square of metres per second, or [[square metre per square second]], is used as a unit of [[gravitational potential]].
== Unicode character == The "metre per second" symbol is encoded by [[Unicode]] at code point {{unichar|33A7|Square M over S}}.<ref name="Unicode-U3300">{{cite web |url=https://www.unicode.org/charts/PDF/U3300.pdf |access-date=May 24, 2019 |title=The Unicode Standard 12.0 – CJK Compatibility ❰ Range: 3300—33FF ❱ |author=Unicode Consortium |author-link=Unicode Consortium |date=2019 |website=Unicode.org }}</ref>
== See also == * [[Orders of magnitude (speed)]] * [[Metre per second squared]] * [[Metre]]
== References == <references> <ref name="Cardarelli2004">{{cite book |author=Cardarelli F. |others=Transl. by MJ Shields. |title=Encyclopaedia of Scientific Units, Weights and Measures: Their SI Equivalences and Origins |edition=3rd revised |publisher=Springer |year=2004 |isbn=978-1852336820 |page=[https://archive.org/details/encyclopaediaofs0000card/page/217 217] |url=https://archive.org/details/encyclopaediaofs0000card/page/217 }}</ref>
<ref name="Dresner1974">{{cite book |author=Dresner S. |title=Units of Measurement: An Encyclopaedic Dictionary of Units Both Scientific and Popular and the Quantities They Measure |year=1974 |publisher=Harvey Miller and Medcalf |isbn=978-0-85602-036-0 |page=13}}</ref>
<ref name="Heijungs2005">{{cite journal |author=Heijungs R. |title=On the Use of Units in LCA |journal=The International Journal of Life Cycle Assessment |year=2005 |volume=10 |issue=3 |doi=10.1065/lca2005.02.199 |page=174|bibcode=2005IJLCA..10..173H |s2cid=110961104 }}</ref>
<ref name="Klein2011">{{cite book |author=Klein HA. |title=The Science of Measurement: A Historical Survey |year=2011 |publisher=Dover Publications |isbn=978-0486258393 |page=695}}</ref> </references>
== External links == * [http://webarchive.loc.gov/all/20150221180343/http://www.bipm.org/en/si/si_brochure/chapter2/2-1/metre.html Official BIPM definition of the metre] * [http://www.bipm.org/en/si/si_brochure/chapter2/2-1/second.html Official BIPM definition of the second]
{{DEFAULTSORT:Metre Per Second}} [[Category:Units of velocity]] [[Category:SI derived units]]