Metre per second
Template:Short description Template:Redirect Template:Infobox unit The metre per second is the unit of both speed (a scalar quantity) and velocity (a 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">Template:Cite web</ref> Template:Val is exactly <math display="inline">\frac{1}{299792458}</math> of the speed of light.
The SI unit symbols are m/s, m·s−1, m s−1, or Template:Sfrac.<ref>Template:Cite web</ref>
Conversions
Template:Val is equivalent to:
- = 3.6 km/h (exactly)<ref>Template:Cite book</ref>
- ≈ 3.2808 feet per second (approximately)<ref>Template:Cite book</ref>
- ≈ 2.2369 miles per hour (approximately)<ref>Template:Cite book</ref>
- ≈ 1.9438 knots (approximately)<ref>Template:Cite book</ref>
1 foot per second = Template:Val (exactly)<ref>Template:Cite book</ref>
1 mile per hour = Template:Val (exactly)<ref>Template:Cite book</ref>
1 km/h = Template:Val (exactly)<ref>Template:Cite book</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 (CGPM).<ref>Template:Cite web</ref> Prior to this, various units such as feet per second, miles per hour, and 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 a vacuum in 1/299,792,458 of a second. The second is defined using the vibration frequency of caesium atoms (9,192,631,770 oscillations per second).<ref>Template:Cite web</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 Template:Unichar.<ref name="Unicode-U3300">Template:Cite web</ref>
See also
References
<references> <ref name="Cardarelli2004">Template:Cite book</ref>
<ref name="Dresner1974">Template:Cite book</ref>
<ref name="Heijungs2005">Template:Cite journal</ref>
<ref name="Klein2011">Template:Cite book</ref> </references>