Joule

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This COMMODITY is about the assemblage of energy. For added uses, see Joule (disambiguation).
Joule
Unit system SI acquired unit
Unit of Energy
Symbol J 
Named after James Prescott Joule
Unit conversions
1 J in ... ... is according to ...
SI abject units 1 kgВ·m2/s2
CGS units 1Г—107 erg
kilowatt hours 2.78Г—10в€’7 kWв‹…h
kilocalories 2.39Г—10в€’4 kcal
BTUs 9.48Г—10в€’4 BTU
electronvolts 6.24Г—1018 eV
The joule (/ˈdʒuːl/ or sometimes /ˈdʒaʊl/), attribute J, is a acquired assemblage of energy, work, or bulk of calefaction in the International System of Units.[1] It is according to the activity expended (or plan done) in applying a force of one newton through a ambit of one accent (1 newton accent or N·m), or in casual an electric accepted of one ampere through a attrition of one ohm for one second. It is called afterwards the English physicist James Prescott Joule (1818–1889).[2][3][4]
In agreement firstly of abject SI units and again in agreement of added SI units:
\rm J = {}\rm \frac{kg \cdot m^2}{s^2} = N \cdot m = \rm Pa \cdot m^3={}\rm W \cdot s = C \cdot V
where kg is the kilogram, m is the metre, s is the second, N is the newton, Pa is the pascal, W is the watt, C is the coulomb, and V is the volt.
One joule can aswell be authentic as:
The plan appropriate to move an electric allegation of one coulomb through an electrical abeyant aberration of one volt, or one '"coulomb volt" (CВ·V). This accord can be acclimated to ascertain the volt.
The plan appropriate to aftermath one watt of ability for one second, or one "watt second" (WВ·s) (compare kilowatt hour). This accord can be acclimated to ascertain the watt.
Contents [hide]
1 Usage
2 Confusion with newton-metre
3 Practical examples
4 Multiples
4.1 Nanojoule
4.2 Microjoule
4.3 Millijoule
4.4 Kilojoule
4.5 Megajoule
4.6 Gigajoule
4.7 Terajoule
4.8 Petajoule
4.9 Exajoule
4.10 Zettajoule
4.11 Yottajoule
5 Conversions
6 See also
7 Notes and references

Usage

This SI assemblage is called afterwards James Prescott Joule. As with every International System of Units (SI) assemblage whose name is acquired from the able name of a person, the aboriginal letter of its attribute is high case (J). However, if an SI assemblage is spelled out in English, it should consistently activate with a lower case letter (joule), except in a bearings area any chat in that position would be capitalized, such as at the alpha of a book or in capitalized actual such as a title. Note that "degree Celsius" conforms to this aphorism because the "d" is lowercase.— Based on The International System of Units, area 5.2.

Confusion with newton-metre

Main article: newton metre
In angular mechanics, torque is akin to the beeline Newtonian mechanics constant of force, moment of apathy to mass, and bend to distance. Activity is the aforementioned in both systems. Thus, although the joule has the aforementioned ambit as the newton-metre (1 J = 1 NВ·m = 1 kgВ·m2В·sв€’2), these units are not interchangeable: the CGPM has accustomed the assemblage of activity the name "joule", but has not accustomed the assemblage of torque any appropriate name, appropriately the assemblage of torque is accepted as the newton-metre (NВ·m) - a admixture name acquired from its basic parts.[5] Torque and activity are accompanying to anniversary added application the equation
E= \tau \theta\
where E is the energy, П„ is the torque, and Оё is the bend confused (in radians). Since radians are dimensionless, it follows that torque and activity accept the aforementioned dimensions.
The use of newton-metres for torque and joules for activity is advantageous in allowance abstain misunderstandings and miscommunications.[5]
An added band-aid is to apprehend that joules are scalars – they are the dot artefact of a agent force and a agent displacement admitting torque is a vector. Torque is the cantankerous artefact of a ambit agent and a force vector. Drawing a acceptable agent arrow over "newton-metre" in a torque resolves the ambiguity.

Practical examples

One joule in accustomed activity represents approximately:
the activity appropriate to lift a baby angel (with a accumulation of about 100 g) angular through one accent of air.
the activity appear if that aforementioned angel avalanche one accent to the ground.
the calefaction appropriate to accession the temperature of 1 g of baptize by 0.24 K.[6]
the archetypal activity appear as calefaction by a being at blow every 1/60 additional (approximately 17 ms).[7]
the active activity of a 50 kg animal affective actual boring (0.2 m/s or 0.72 km/h).
the active activity of a 56 g tennis brawl affective at 6 m/s (22 km/h).[8]
the active activity of an article with accumulation 1 kg affective at √2 ≈ 1.4 m/s.
Since the joule is aswell a watt-second and the accepted assemblage for electricity sales to homes is the kWВ·h (kilowatt-hour), a kWВ·h is appropriately 1000 (kilo) Г— 3600 abnormal = 3.6 MJ (megajoules).

Multiples

Rewritten Article For added examples, see: Orders of consequence (energy)
SI multiples for joule (J)
Submultiples Multiples
Value Symbol Name Value Symbol Name
10в€’1 J dJ decijoule 101 J daJ decajoule
10в€’2 J cJ centijoule 102 J hJ hectojoule
10в€’3 J mJ millijoule 103 J kJ kilojoule
10в€’6 J ВµJ microjoule 106 J MJ megajoule
10в€’9 J nJ nanojoule 109 J GJ gigajoule
10в€’12 J pJ picojoule 1012 J TJ terajoule
10в€’15 J fJ femtojoule 1015 J PJ petajoule
10в€’18 J aJ attojoule 1018 J EJ exajoule
10в€’21 J zJ zeptojoule 1021 J ZJ zettajoule
10в€’24 J yJ yoctojoule 1024 J YJ yottajoule
Common multiples are in adventurous face
Nanojoule[edit]
The nanojoule (nJ) is according to one billionth (10-9) of one joule. One nanojoule is about 1/160 of the active activity of a aerial mosquito.[9]
Microjoule[edit]
The microjoule (ОјJ) is according to one millionth (10-6) of one joule. The Large Hadron Collider (LHC) is accepted to aftermath collisions on the adjustment of 1 microjoule (7 TeV) per particle.
Millijoule[edit]
The millijoule (mJ) is according to one thousandth (10-3) of a joule.
Kilojoule[edit]
The kilojoule (kJ) is according to one thousand (103) joules. Nutritional aliment labels in assertive countries accurate activity in kilojoules (kJ).
One kilojoule per additional (1 kilowatt) is about the bulk of solar radiation accustomed by one aboveboard accent of the Earth in abounding daylight.[10]
Megajoule[edit]
The megajoule (MJ) is according to one actor (106) joules, or about the active activity of a one-tonne car affective at 160 km/h (100 mph).
Because 1 watt times 1 additional equals 1 joule, 1 kilowatt-hour is 1000 watts times 3600 seconds, or 3.6 megajoules.
Gigajoule[edit]
The gigajoule (GJ) is according to one billion (109) joules. 6 GJ is about the bulk of abeyant actinic activity in a butt of oil, if combusted.[11]
Terajoule[edit]
The terajoule (TJ) is according to one abundance (1012) joules. About 63 TJ of activity was appear by the diminutive bomb that exploded over Hiroshima.[12] The International Space Station, with a accumulation of about 450,000 kg and alternate acceleration of 7.7 km/s,[13] has a active activity of almost 13 TJ.
Petajoule[edit]
The petajoule (PJ) is according to one quadrillion (1015) joules. 210 PJ is agnate to about 50 megatons of TNT. This is the bulk of activity appear by the Tsar Bomba, the better counterfeit nuclear access ever.
Exajoule[edit]
The exajoule (EJ) is according to one quintillion (1018) joules. The 2011 TЕЌhoku convulsion and tsunami in Japan had 1.41 EJ of activity according to its 9.0 on the moment consequence scale. Activity in the United States acclimated per year is almost 94 EJ.
Zettajoule[edit]
The zettajoule (ZJ) is according to one sextillion (1021) joules. Annual all-around activity burning is about 0.5 ZJ.
Yottajoule[edit]
The yottajoule (YJ) is according to one septillion (1024) joules. This is about the bulk of activity appropriate to calefaction the absolute aggregate of baptize on Earth by 1 В°C. The thermal achievement of the Sun is about 400 YJ per second.

Conversions

Main article: Conversion of units of energy
1 joule is according to:
1Г—107 ergs (exactly)
6.24150974Г—1018 eV (electronvolts)
0.2390 cal (thermochemical gram calories or baby calories)
2.3901Г—10в€’4 kcal (thermochemical kilocalories, kilogram calories, ample calories or aliment calories)
9.4782Г—10в€’4 BTU (British thermal unit)
0.7376 ftВ·lb (foot-pounds)
23.7 ftВ·pdl (foot-poundals)
2.7778Г—10в€’7 kilowatt-hour
2.7778Г—10в€’4 watt-hour
9.8692Г—10в€’3 litre-atmosphere
11.1265 femtograms (mass-energy equivalence)
1Г—10в€’44 foe (exactly)
Units authentic absolutely in agreement of the joule include:
1 thermochemical calorie = 4.184 J[14]
1 International Table calorie = 4.1868 J[15]
1 watt hour = 3600 J
1 kilowatt hour = 3.6Г—106 J (or 3.6 MJ)
1 watt additional = 1 J
1 ton TNT = 4.184 GJ