Dyne
The dyne (symbol dyn, from Greek δύναμις, dynamis, meaning power, force) is a derived unit of force specified in the centimetre–gram–second (CGS) system of units, a predecessor of the modern SI.
Contents
History
The name dyne was first proposed as a C.G.S. unit of force in 1873 by a Committee of the British Association for the Advancement of Science.^{[1]}
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".^{[2]} An equivalent definition for one dyne is "that force which, acting for one second, will produce unit change of velocity in a mass of one gram"^{[3]}
One dyne is equal to 10 micronewtons, 10^{−5} N or to 10 nsn (nanosthenes) in the old metre–tonne–second system of units.
- 1 dyn = 1 g⋅cm/s^{2} = 10^{−5} kg⋅m/s^{2} = 10^{−5} N
- 1 N = 1 kg⋅m/s^{2} = 10^{5} g⋅cm/s^{2} = 10^{5} dyn
newton (SI unit) |
dyne |
kilogram-force, kilopond |
pound-force | poundal | |
---|---|---|---|---|---|
1 N | ≡ 1 kg⋅m/s^{2} | = 10^{5} dyn | ≈ 0.10197 kp | ≈ 0.22481 lbf | ≈ 7.2330 pdl |
1 dyn | = 10^{−5} N | ≡ 1 g⋅cm/s^{2} | ≈ 1.0197 × 10^{−6} kp | ≈ 2.2481 × 10^{−6} lbf | ≈ 7.2330 × 10^{−5} pdl |
1 kp | = 9.80665 N | = 980665 dyn | ≡ g_{n} ⋅ (1 kg) | ≈ 2.2046 lbf | ≈ 70.932 pdl |
1 lbf | ≈ 4.448222 N | ≈ 444822 dyn | ≈ 0.45359 kp | ≡ g_{n} ⋅ (1 lb) | ≈ 32.174 pdl |
1 pdl | ≈ 0.138255 N | ≈ 13825 dyn | ≈ 0.014098 kp | ≈ 0.031081 lbf | ≡ 1 lb⋅ft/s^{2} |
The value of g_{n} as used in the official definition of the kilogram-force is used here for all gravitational units. |
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 °C (77 °F).^{[4]} (In SI units this is ×10^{−3} N/m or 71.99.) 71.99 mN/m
See also
References
- ^ Thomson, Sir W; Professor GC, Foster; Maxwell, Professor JC; Stoney, Mr GJ; Professor Flemming, Jenkin; Siemens, Dr; Bramwell, Mr FJ (September 1873). Everett, Professor, ed. First Report of the Committee for the Selection and Nomenclature of Dynamical and Electrical Units. Forty-third Meeting of the British Association for the Advancement of Science. Bradford: Johna Murray. p. 223. Retrieved 8 April 2012.
- ^ Gyllenbok, Jan. "dyne". Encyclopaedia of Historical Metrology, Weights, and Measures, Volume 1. Birkhäuser. p. 90. ISBN 9783319575988. Retrieved 20 April 2018.
- ^ "Dyne". The New Student's Reference Work. Chicago: Compton. 1914.
- ^ Haynes, W.M.; Lide, D. R.; Bruno, T.J., eds. (2015). "Surface tension of common liquids". CRC Handbook of Chemistry and Physics (96nd ed.). CRC Press. p. 6-181. ISBN 9781482260977.