Dyne

For people with the name, see Dyne (name).

dyne
Unit system	CGS units
Unit of	force
Symbol	dyn
Conversions
1 dyn in ...	... is equal to ...
CGS base units	1 g⋅cm/s^2
SI units	10^−5 N
British Gravitational System	2.248089×10^−6 lbf

The dyne (symbol: dyn; from Ancient Greek δύναμις (dúnamis) 'power, force') is a derived unit of force specified in the centimetre–gram–second (CGS) system of units, a predecessor of the modern 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.^[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 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".^[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/s² = 10⁻⁵ kg⋅m/s² = 10⁻⁵ N
• 1 N = 1 kg⋅m/s² = 10⁵ g⋅cm/s² = 10⁵ dyn

Units of force

v t e	newton	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	≡ gn × 1 kg	≈ 2.2046 lbF	≈ 70.932 pdl
1 lbF	≈ 4.448222 N	≈ 444822 dyn	≈ 0.45359 kp	≡ gn × 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 gn (9.80665 m/s^2) 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 71.99×10⁻³ N/m or 71.99 mN/m.)

See also

• Centimetre–gram–second system of units
• Erg

References

1. Thomson, Sir Wl; 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. 224. Retrieved 8 April 2012.
2. Gyllenbok, Jan (11 April 2018). "dyne". Encyclopaedia of Historical Metrology, Weights, and Measures. Vol. 1. Birkhäuser. p. 90. ISBN 9783319575988. Retrieved 20 April 2018.
3. Beach, Chandler B., ed. (1914). "Dyne" . The New Student's Reference Work . Vol. II. Chicago: F. E. Compton and Co.
4. 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.