View source for Dyne

{{Short description|Unit of force in the CGS system}}
{{For|people with the name|Dyne (name)}}
{{Infobox unit
| bgcolor       = 
| name          = dyne
| image         = Elastic hysteresis lab d 3.2 N wsulake (cropped; rotated).JPG
| caption       = Ohaus [[spring scale]] displaying force measurements in both [[newton (unit)|newton]]s and dynes 
| standard      = [[CGS units]]
| quantity      = [[force]]
| symbol        = dyn
| symbol2       = 
| extralabel    = 
| extradata     = 
| units1        = CGS base units
| inunits1      = 1 g⋅cm/s<sup>2</sup>
| units2        = [[SI units]]
| inunits2      = {{val|e=-5|u=N}}
| units3        = [[British Gravitational System]]
| inunits3      = {{convert|1|dyn|lbf|sigfig=7|disp=out}}
}}

The '''dyne''' (symbol: '''dyn'''; {{etymology|grc|''{{wikt-lang|grc|δύναμις}}'' ({{grc-transl|δύναμις}})|power, force}}) is a derived [[units of measurement|unit]] of [[force (physics)|force]] specified in the [[centimetre–gram–second system of units|centimetre–gram–second]] (CGS) system of units, a predecessor of the modern [[International System of Units|SI]].

== History ==
The name ''dyne'' was first proposed as a CGS unit of force in 1873 by a Committee of the [[British Association for the Advancement of Science]], and is from [[Ancient Greek]] {{lang |grc |δύναμις}} ('force', 'power').<ref>{{cite conference 
|url= https://www.biodiversitylibrary.org/item/94452#page/7/mode/1up
|title=First Report of the Committee for the Selection and Nomenclature of Dynamical and Electrical Units 
|date=September 1873
|conference= Forty-third Meeting of the British Association for the Advancement of Science
|editor-first= Professor 
|editor-last = Everett
|first1=Sir Wl
|last1 = Thomson
|first2 = Foster
|last2 = Professor GC
|first3 = Professor JC
|last3 = Maxwell
|first4 = Mr GJ
|last4 = Stoney
|first5 = Jenkin
|last5 = Professor Flemming
|first6 = Dr
|last6 = Siemens
|first7 = Mr FJ 
|last7 = Bramwell  
|publisher= Johna Murray
|location= Bradford
|page = 224
|access-date= 8 April 2012}}</ref>

==Definition==
The dyne is defined as "the force required to accelerate a [[mass]] of one [[gram]] at a rate of one [[centimetre]] per [[second]] squared".<ref>{{cite encyclopedia |last=Gyllenbok |first=Jan |author-link=Jan Gyllenbok |date=11 April 2018 |page=90 |title=dyne |encyclopedia=Encyclopaedia of Historical Metrology, Weights, and Measures |volume=1 |url=https://books.google.com/books?id=XnRVDwAAQBAJ&pg=PA90 |access-date=20 April 2018 |publisher=Birkhäuser |isbn=9783319575988 }}</ref> An equivalent definition of the dyne is "that force which, acting for one second, will produce a change of velocity of one centimetre per second in a mass of one gram".<ref>{{Cite NSRW |wstitle= Dyne |volume= II |page= | last= |first= |author-link= |year=1914| short=}}</ref>  

One dyne is equal to 10 micronewtons, 10<sup>−5</sup> [[newton (unit)|N]] or to 10 nsn (nano[[sthene]]s) in the old [[metre–tonne–second system of units]]. 
* 1 dyn = 1 g⋅cm/s<sup>2</sup> = 10<sup>−5</sup> kg⋅m/s<sup>2</sup> = 10<sup>−5</sup> N
* 1 N = 1&nbsp;kg⋅m/s<sup>2</sup> = 10<sup>5</sup> g⋅cm/s<sup>2</sup> = 10<sup>5</sup> dyn
{{Units of force}}

==Use==
The '''dyne per centimetre''' is a unit traditionally used to measure [[surface tension]]. For example, the surface tension of distilled water is 71.99 dyn/cm at 25&nbsp;°C (77&nbsp;°F).<ref>{{cite book | editor = Haynes, W.M. | editor2=Lide, D. R. | editor3=Bruno, T.J. | chapter = Surface tension of common liquids  | title = CRC Handbook of Chemistry and Physics | edition = 96nd | publisher = CRC Press |isbn =  9781482260977 |url = https://books.google.com/books?id=RpLYCQAAQBAJ| year = 2015| page=6-181
}}</ref> (In SI units this is {{val|71.99|e=-3|u=N/m}} or {{val|71.99|u=mN/m}}.)  

==See also==
* [[Centimetre–gram–second system of units]]
* [[Erg]]

== References ==
{{reflist}}

{{CGS units}}

[[Category:Centimetre–gram–second system of units]]