Dyne
Unit of force in the CGS system
From Wikipedia, the free encyclopedia
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.
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| dyne | |
|---|---|
Ohaus spring scale displaying force measurements in both newtons and dynes | |
| General information | |
| Unit system | CGS units |
| Unit of | force |
| Symbol | dyn |
| Conversions | |
| 1 dyn in ... | ... is equal to ... |
| CGS base units | 1 g⋅cm/s2 |
| SI units | 10−5 N |
| British Gravitational System | 2.248089×10−6 lbf |
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
| Newtons | Dynes | Kilograms-force kiloponds |
Pounds | Poundals | |
|---|---|---|---|---|---|
| 1 N | ≡ 1 kg⋅m⁄s2 | = 100000 dyn | ≈ 0.10197 kgf | ≈ 0.22481 lb | ≈ 7.23301 pdl |
| 1 dyn | = 1×10−5 N | ≡ 1 g⋅cm⁄s2 | ≈ 1.01972×10−6 kgf | ≈ 2.24809×10−6 lb | ≈ 7.23301×10−5 pdl |
| 1 kgf | = 9.80665 N | = 980665 dyn | ≡ gn × 1 kg | ≈ 2.20462 lb | ≈ 70.9316 pdl |
| 1 lb | ≈ 4.44822 N | ≈ 444822 dyn | ≈ 0.45359 kgf | ≡ gn × 1 lbm / .3048 m⁄ft | ≈ 32.1740 pdl |
| 1 pdl | ≈ 0.13825 N | ≈ 13825.5 dyn | ≈ 0.01410 kgf | ≈ 0.03108 lbf | ≡ 1 lbm⋅ft⁄s2 |
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.)