Energy and Work

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The following units are included in this section:

 

ID

Unit

Definition

Wikipedia page and other notes

1

joule (J)
(kg·m2/s2)

-

https://en.wikipedia.org/wiki/Joule

Equivalent to watt second and newton metre

2

kilojoule (kJ)

103 J

https://en.wikipedia.org/wiki/Joule#Kilojoule

Equivalent to kilowatt second

3

megajoule (MJ)

106 J

https://en.wikipedia.org/wiki/Joule#Megajoule

4

gigajoule (GJ)

109 J

https://en.wikipedia.org/wiki/Joule#Gigajoule

5

terajoule (TJ)

1012 J

https://en.wikipedia.org/wiki/Joule#Terajoule

6

petajoule (PJ)

1015 J

https://en.wikipedia.org/wiki/Joule#Petajoule

7

millijoule (mJ)

10-3 J

https://en.wikipedia.org/wiki/Joule#Millijoule

8

microjoule (µJ)

10-6 J

https://en.wikipedia.org/wiki/Joule#Microjoule

9

nanojoule (nJ)

10-9 J

https://en.wikipedia.org/wiki/Joule#Nanojoule

10

picojoule (pJ)

10-12 J

 

11

femtojoule (fJ)

10-15 J

 

12

erg

10-7 J

https://en.wikipedia.org/wiki/Erg

13

pound-force inch (lbf·in)

0.1129848290276167 J

 

14

pound-force foot (lbf·ft)

12 lbf·in

https://en.wikipedia.org/wiki/Foot-pound_(energy)

15

ounce-force inch (ozf·in)

 

0.00706155181422604375 J

 

16

ounce-force foot (ozf·ft)

12 ozf·in

 

17

watt hour (W·h)

3600 J

https://en.wikipedia.org/wiki/Kilowatt_hour#Watt_hour_multiples_and_billing_units

18

watt second (W·s)

1 J

https://en.wikipedia.org/wiki/Watt_second

Equivalent to Joule and newton metre

19

kilowatt second (kW·s)

103 J

https://en.wikipedia.org/wiki/Watt_second

Page refers to watt second

Equivalent to kilojoule

20

kilowatt hour (kW·h)

3.6×106 J

https://en.wikipedia.org/wiki/Kilowatt_hour

21

megawatt hour (MW·h)

3.6×109 J

https://en.wikipedia.org/wiki/Kilowatt_hour#Watt_hour_multiples_and_billing_units

22

gigawatt  hour (GW·h)

3.6×1012 J

https://en.wikipedia.org/wiki/Kilowatt_hour#Watt_hour_multiples_and_billing_units

23

terawatt  hour (TW·h)

3.6×1015 J

https://en.wikipedia.org/wiki/Kilowatt_hour#Watt_hour_multiples_and_billing_units

24

petawatt   hour (PW·h)

3.6×1018 J

https://en.wikipedia.org/wiki/Kilowatt_hour#Watt_hour_multiples_and_billing_units

25

milliwatt hour (mW·h)

3.6 J

https://en.wikipedia.org/wiki/Kilowatt_hour

26

microwatt hour (μW·h)

3.6×10-3 J

https://en.wikipedia.org/wiki/Kilowatt_hour

27

newton metre (N·m)

1 J

https://en.wikipedia.org/wiki/Newton_metre

Equivalent to Joule and watt second

28

newton centimetre (N·cm)

10-2 J

 

29

newton millimetre (N·mm)

10-3 J

 

30

dyne metre (dyn·m)

10-5 J

 

31

dyne centimetre (dyn·cm)

10-7 J

 

32

dyne millimetre (dyn·mm)

10-8 J

 

33

kilopond metre (kp·m)

9.80665 J

The same as “kilogram-force metre”

34

kilopond centimetre (kp·cm)

9.80665×10-2 J

The same as “kilogram-force centimetre”

35

kilopond millimetre (kp·mm)

9.80665×10-3 J

The same as “kilogram-force millimetre”

36

kilogram-force metre (kgf·m)

9.80665 J

The same as “kilopond metre”

37

kilogram-force centimetre (kgf·cm)

9.80665×10-2 J

The same as “kilopond centimetre”

38

kilogram-force millimetre (kgf·mm)

9.80665×10-3 J

The same as “kilopond millimetre”

39

gram-force metre

9.80665×10-3 J

 

40

gram-force centimetre

9.80665×10-5 J

 

41

gram-force millimetre

9.80665×10-6 J

 

42

poundal inch (pdl·in)

0.0035116758411504 J

 

43

poundal foot (pdl·ft)

12 pdl·in

https://en.wikipedia.org/wiki/Foot-poundal

44

foe

1044 J

https://en.wikipedia.org/wiki/Foe_(unit)

45

calorie [IT] (cal-IT)

4.1868 J

https://en.wikipedia.org/wiki/Calorie

It is defined as 4.1868 J exactly. This definition was adopted by the Fifth International Conference on Properties of Steam (London, July 1956)

46

calorie [Thermochemical TH] (cal-TH)

4.184 J

https://en.wikipedia.org/wiki/Calorie

It is defined as 4.184 J exactly

47

calorie [15 °C] (cal15)

4.1855 J

https://en.wikipedia.org/wiki/Calorie

15 °C calorie, defined as 4.1855 J exactly (Comité international des poids et mesures (International Committee for Weights and Measures) 1950; PV, 1950, 22, 79–80)

48

kilocalorie [IT] (kcal-IT)

4,186.8 J

https://en.wikipedia.org/wiki/Calorie

Page referes to Calorie

49

kilocalorie [Thermochemical TH] (kcal-TH)

4,184 J

https://en.wikipedia.org/wiki/Calorie

Page referes to Calorie

50

kilocalorie [15 °C] (kcal15)

4,185.5 J

https://en.wikipedia.org/wiki/Calorie

Page refers to Calorie

51

BTU [IT]

1,055.05585262 J

https://en.wikipedia.org/wiki/British_thermal_unit

The most widespread BTU uses the International Steam Table (IT) calorie, which was defined by the Fifth International Conference on the Properties of Steam (London, July 1956) to be exactly 4.1868 J.

The value of 1055.05585262 J for BTU [IT] is also exact.

Note: A BTU was originally defined as the amount of heat required to raise the temperature of 1 avoirdupois pound of liquid water by 1 degree Fahrenheit at a constant pressure of one atmosphere. As with the calorie, several definitions of the Btu exist, because the temperature response of water to heat energy is non-linear. This means that the change in temperature of a water mass caused by adding a certain amount of heat to it will be a function of the water's initial temperature. Definitions of the Btu based on different water temperatures can therefore vary by up to 0.5%.

Source: https://en.wikipedia.org/wiki/British_thermal_unit

52

BTU [Thermochemical TH]

1,054.35026444 J

https://en.wikipedia.org/wiki/British_thermal_unit

Uses the "thermochemical calorie" of exactly 4.184 J.

The value of 1054.35026444 J is also exact

53

BTU [US, 59 °F (15 °C)]

1,054.804 J

(Value may not be exact)

https://en.wikipedia.org/wiki/British_thermal_unit

Amount of energy required to raise 1 lbm of water by 1°F using the 15° calorie. Chiefly American. Defined as 1054.804 J

THIS VALUE MAY NOT BE 100% EXACT, ALTHOUGH IT IS THE TYPICAL AND ONLY VALUE FOUND IN THE LITERATURE FOR THIS UNIT

54

therm [IT] (thm-IT)

105 BTU [IT]

https://en.wikipedia.org/wiki/Therm

The value of 105,505,585.262 J is exact

55

therm [TH] (thm-TH)

105 BTU [Thermochemical TH]

https://en.wikipedia.org/wiki/Therm

The value of 105,435,026.444 J is exact

56

therm [US, 59 °F (15.0 °C)] (thm-US)

105 BTU [US, 59 °F (15 °C)]

https://en.wikipedia.org/wiki/Therm

The value of 105,435,026.444 J is exact

57

ton of TNT

4.184×109 J

https://en.wikipedia.org/wiki/Ton#Units_of_energy_and_power

A ton of TNT is equal to 109 thermochemical calories

58

kiloton of TNT

4.184×1012 J

https://en.wikipedia.org/wiki/Ton#Units_of_energy_and_power

59

megaton of TNT

4.184×1015 J

https://en.wikipedia.org/wiki/Ton#Units_of_energy_and_power

60

electronvolt (eV)

1.6021766208×10-19 J

(Value may not be exact)

https://en.wikipedia.org/wiki/Electronvolt

 

THIS VALUE MAY NOT BE 100% EXACT, ALTHOUGH IT IS THE TYPICAL VALUE FOUND IN THE LITERATURE FOR THIS UNIT

 

Note: The electronvolt is by definition the amount of energy gained (or lost) by the charge of a single electron moving across an electric potential difference of one volt. Thus it is 1 volt multiplied by the elementary charge (1.6021766208(98)×10-19 C). Therefore, one electronvolt is equal to 1.6021766208(98)×10-19 J.

Source: https://en.wikipedia.org/wiki/Elementary_charge

 

Here, the value of 1.6021766208×10-19 C is used as the value for the elementary charge. The number in parentheses (98) describes the uncertainty in the measurement. The same value is reported in Wikipedia and also here:

http://physics.nist.gov/cgi-bin/cuu/Value?evj

http://docs.scipy.org/doc/scipy/reference/constants.html

 

But a slightly different value (1.602176565(35)) can be found in the following:

http://units.wikia.com/wiki/Electronvolt

http://arxiv.org/pdf/1203.5425.pdf (Page 72)

 

61

millielectronvolt (meV)

10-3 eV

https://en.wikipedia.org/wiki/Electronvolt

Page referes to electronvolt

62

kiloelectronvolt (meV)

103 eV

https://en.wikipedia.org/wiki/Electronvolt

Page referes to electronvolt

63

megaelectronvolt (MeV)

106 eV

https://en.wikipedia.org/wiki/Electronvolt

Page referes to electronvolt

64

gigaelectronvolt (GeV)

109 eV

https://en.wikipedia.org/wiki/Electronvolt

Page referes to electronvolt

65

teraelectronvolt (TeV)

1012 eV

https://en.wikipedia.org/wiki/Electronvolt

Page referes to electronvolt

 

 

The above definitions of the various units are EXACT with the exception of the two cases that are highlighted in red color.

Note: In the above, a period (.) is used to indicate the decimal place and a comma (,) is used to separate groups of thousands.

 

Type of conversion relationship: DIRECTLY PROPORTIONAL (y=ax)

Example conversion diagram (see two units in bold above):

Energy