Slug (unit)

Source: Wikipedia, the free encyclopedia.
For railway locomotive, see Slug (railroad).
slug
Unit systemBritish Gravitational system
Unit ofMass
Symbolslug
Conversions
1 slug in ...... is equal to ...
   BGS base units   1 ft−1⋅lbf⋅s2
   SI units   14.59390 kg
   US customary units   32.17404 lb

The slug is a derived unit of

system of measures, most notably within the British Imperial measurement system and the United States customary measures system. Systems of measure either define mass and derive a force unit or define a base force and derive a mass unit[1] (cf. poundal, a derived unit of force in a force-based system). A slug is defined as a mass that is accelerated by 1 ft/s2 when a net force of one pound (lbf) is exerted on it.[2]

One slug is a mass equal to 32.17405 lb (14.59390 kg) based on standard gravity, the international foot, and the avoirdupois pound.[3] In other words, at the Earth's surface (in standard gravity), an object with a mass of 1 slug weighs approximately 32.17405 lbf or 143.1173 N.[4][5]

History

The slug is part of a subset of units known as the

gravitational FPS system, one of several such specialized systems of mechanical units developed in the late 19th and the early 20th century. Geepound was another name for this unit in early literature.[6]

The name "slug" was coined before 1900 by British physicist Arthur Mason Worthington,[7] but it did not see any significant use until decades later.[8] It is derived from the meaning "solid block of metal" (cf. "slug" fake coin or "slug" projectile), not from the slug mollusc.[9] A 1928 textbook says:

No name has yet been given to the unit of mass and, in fact, as we have developed the theory of dynamics no name is necessary. Whenever the mass, m, appears in our formulae, we substitute the ratio of the convenient force-acceleration pair (w/g), and measure the mass in lbs. per ft./sec.2 or in grams per cm./sec.2.

— Noel Charlton Little, College Physics, Charles Scribner's Sons, 1928, p. 165.
Three approaches to units of mass and force or weight[10][11]
Base 		Force Weight Mass
2nd law of motion m = F/a F = W ⋅ a/g F = m ⋅ a
System
BG
 GM EE M
AE
 CGS MTS SI
Acceleration (a) ft/s2 m/s2 ft/s2 m/s2 ft/s2 Gal m/s2 m/s2
Mass (m) slug
hyl
 pound-mass kilogram pound gram tonne kilogram
Force (F),
weight (W) 		pound
kilopond
 pound-force kilopond poundal dyne sthène newton
Pressure (p) pound per square inch
technical atmosphere
 pound-force per square inch standard atmosphere poundal per square foot barye
pieze
 pascal

The slug is listed in the Regulations under the Weights and Measures (National Standards) Act, 1960. This regulation defines the units of weights and measures, both regular and metric, in Australia.

Related units

The

portmanteau of the words slug and inch),[13][14] slugette,[15] or snail.[16] It is equivalent to 386.0886 pounds (175.1268 kg) based on standard gravity.[3]

Similar (but long-obsolete) metric units included the glug (980.665 g) in a gravitational system related to the

metre–kilogram–second system.[19]

See also

References

  1. ^ See Elementary High School physics and chemistry text books/fundamentals.
  2. ^ Collins, Danielle (May 2019). "How to convert between mass and force — in metric and English units". Linear Motion Tips. Retrieved 18 January 2021.
  3. ^
    ISBN 0-07-365939-8
    .
  4. ISBN 0-201-56947-7
    .
  5. ^ Shevell, R.S. Fundamentals of Flight, Second ed, p. xix. Prentice-Hall, 1989.
  6. ^ gee Archived 2018-01-27 at the Wayback Machine. unit2unit.eu
  7. ^ Worthington, Arthur Mason (1900). Dynamics of Rotation: An Elementary Introduction to Rigid Dynamics (3rd ed.). Longmans, Green, and Co. p. 9.
  8. ISBN 9783319575988
    – via Google Books.
  9. ^ Society, Digital Equipment Computer Users (September 4, 1965). "Papers and Presentations" – via Google Books.
  10. doi:10.1021/ie50367a028
    .
  11. doi:10.1021/ie50712a010
    .
  12. ISBN 0831133678
    .
  13. ^ Slug Archived 2016-11-30 at the Wayback Machine. DiracDelta Science & Engineering Encyclopedia
  14. ^ "1 blob". Wolfram Alpha Computational Knowledge Engine. Retrieved 27 October 2011.
  15. ^ Celmer, Robert. Notes to Accompany Vibrations II. Version 2.2. 2009.
  16. ^ Rowlett, Russ. "How Many? A Dictionary of Units of Measurement". unc.edu, September 1, 2004. Retrieved January 26, 2018.
  17. ISBN 1-85233-682-X
    .
  18. doi:10.1119/1.1934599
    .
  19. ISBN 1-85233-682-X
    .

External links
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