259:
The value adopted in the
International Service of Weights and Measures for the standard acceleration due to Earth's gravity is 980.665 cm/s, value already stated in the laws of some countries.
248:. This task was given to Gilbert Étienne Defforges of the Geographic Service of the French Army. The value he found, based on measurements taken in March and April 1888, was 9.80991(5) m⋅s.
122:(without a suffix) can also mean the local acceleration due to local gravity and centrifugal acceleration, which varies depending on one's position on Earth (see
99:
from the rotation of the Earth (but the latter is small enough to be negligible for most purposes); the total (the apparent gravity) is about 0.5% greater at the
565:
226:
of 760 mm. But since that weight depends on the local gravity, they now also needed a standard gravity. The 1887 CIPM meeting decided as follows:
207:
645:
M. Amalvict (2010). "Chapter 12. Absolute gravimetry at BIPM, Sèvres (France), at the time of Dr. Akihiko Sakuma". In
Stelios P. Mertikas (ed.).
517:
540:
245:
174:
of 45°. Although the actual acceleration of free fall on Earth varies according to location, the above standard figure is always used for
252:
80:
170:
defined above is a nominal midrange value on Earth, originally based on the acceleration of a body in free fall at sea level at a
222:, the CIPM needed to define a standard atmospheric pressure. The definition they chose was based on the weight of a column of
654:
629:
244:
All that was needed to obtain a numerical value for standard gravity was now to measure the gravitational strength at the
272:
was, in accordance with the 1887 CIPM declaration, obtained by dividing
Defforges's result – 980.991 cm⋅s in the
548:
187:
510:
711:
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701:
240:) divided by 1.0003322, the theoretical coefficient required to convert to a latitude of 45° at sea level.
251:
This result formed the basis for determining the value still used today for standard gravity. The third
280:– by 1.0003322 while not taking more digits than warranted considering the uncertainty in the result.
50:
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139:
91:. The acceleration of a body near the surface of the Earth is due to the combined effects of
603:
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8:
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is equal to the acceleration due to gravity at the
International Bureau (alongside the
123:
650:
625:
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223:
152:
is also used as a unit for any form of acceleration, with the value defined as above.
100:
96:
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618:
From
Artefacts to Atoms: The BIPM and the Search for Ultimate Measurement Standards
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Gravity, Geoid and Earth
Observation: IAG Commission 2: Gravity Field
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255:, held in 1901, adopted a resolution declaring as follows:
143:
520:. p. 52. NIST special publication 330, 2008 edition.
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of an object as the product of its mass and this nominal
509:
Taylor, Barry N.; Thompson, Ambler, eds. (March 2008).
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purposes. In particular, since it is the ratio of the
190:
SI units is the ratio of the kilogram-force and the
79: ft/s). This value was established by the 3rd
218:of water. Since the boiling point varies with the
579:. Arlington, Texas: S.A.W.E., Inc. Archived from
693:
290:Conversions between common units of acceleration
208:International Committee for Weights and Measures
206:Already in the early days of its existence, the
518:National Institute of Standards and Technology
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83:(1901, CR 70) and used to define the standard
541:International Bureau of Weights and Measures
16:Standard gravitational acceleration on Earth
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615:
253:General Conference on Weights and Measures
81:General Conference on Weights and Measures
606:, Cornell University, retrieved June 2007
116:is sometimes used for standard gravity,
563:
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533:The International System of Units (SI)
511:The international system of units (SI)
210:(CIPM) proceeded to define a standard
186:, its numeric value when expressed in
233:standard acceleration due to gravity
671:"Resolution of the 3rd CGPM (1901)"
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25:standard acceleration of free fall
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21:standard acceleration of gravity
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263:The numeric value adopted for
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649:. Springer. pp. 84–85.
132:should not be confused with
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568:Precise Measurement of Mass
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10:
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604:"Curious About Astronomy?"
543:. 2006. pp. 142–143.
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51:gravitational acceleration
564:Boynton, Richard (2001).
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97:centrifugal acceleration
57:near the surface of the
622:Oxford University Press
142:, or g, the symbol for
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140:gravitational constant
27:, often called simply
712:Units of acceleration
257:
228:
616:Terry Quinn (2011).
246:International Bureau
238:Pavillon de Breteuil
220:atmospheric pressure
110:Although the symbol
702:Physical quantities
577:Sawe Paper No. 3147
490:Theoretical gravity
292:
63:defined by standard
61:. It is a constant
288:
230:The value of this
53:of an object in a
656:978-3-642-10634-7
631:978-0-19-530786-3
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124:Earth's gravity
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31:and denoted by
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196:units of force
180:kilogram-force
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126:). The symbol
45:
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678:. Retrieved
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588:. Retrieved
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212:thermometric
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176:metrological
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103:than at the
89:acceleration
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480:Gravity map
303:, or cm/s)
296:Base value
284:Conversions
696:Categories
590:2007-01-21
516:(Report).
496:References
155:See also:
717:Constants
680:July 19,
469:See also
278:en vogue
188:coherent
184:kilogram
182:and the
707:Gravity
448:32.1740
443:980.665
375:30.4800
371:1 ft/s
224:mercury
202:History
157:g-force
105:Equator
93:gravity
653:
628:
547:
402:1 m/s
194:, two
192:newton
146:. The
138:, the
85:weight
74:32.174
55:vacuum
584:(PDF)
573:(PDF)
537:(PDF)
514:(PDF)
453:9.806
424:0.101
411:3.280
393:0.031
385:0.304
358:1.019
345:0.032
101:poles
67:9.806
59:Earth
682:2015
675:BIPM
651:ISBN
626:ISBN
545:ISBN
395:0810
353:0.01
347:8084
308:ft/s
144:gram
95:and
19:The
426:972
406:100
387:800
315:m/s
301:Gal
274:cgs
65:as
40:or
23:or
698::
673:.
620:.
575:.
455:65
433:1
413:84
365:10
360:72
331:)
324:,
317:)
310:)
198:.
107:.
76:05
69:65
684:.
659:.
634:.
593:.
570:"
566:"
553:.
461:1
438:0
435:g
419:1
380:1
363:×
340:1
329:0
326:g
320:(
313:(
306:(
299:(
269:0
266:ɡ
167:0
164:ɡ
149:ɡ
135:G
129:ɡ
119:ɡ
113:ɡ
46:n
43:ɡ
37:0
34:ɡ
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