The dyne (symbol: dyn; ) is a derived unit of force specified in the centimetreâÂÂgramâÂÂsecond (CGS) system of units, a predecessor of the modern SI.
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.
The dyne is defined as "the force required to accelerate a mass of one gram at a rate of one centimetre per second squared". 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".
One dyne is equal to 10 micronewtons, 10<sup>âÂÂ5</sup> N or to 10 nsn (nanosthenes) in the old metreâÂÂtonneâÂÂsecond system of units.
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 ðC (77 ðF). (In SI units this is or .)