Units of Energy - Maple Help

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Units of Energy

 

Description

Examples

Description

• 

Energy has the dimension mass length squared per time squared. The SI unit of energy is the joule, which is defined as a kilogram meter squared per second squared.

• 

Work and heat are physical quantities with the same dimension as energy.

• 

Maple knows the units of energy listed in the following table. The context IT indicates International Table.

Name

Symbols

Context

Alternate Spellings

Prefixes

 

 

 

 

 

joule

J

SI *

joules

SI

electronvolt

eV

SI *

electronvolts

SI

hartree

E0

Atomic *

hartrees

SI

erg

 

standard *

ergs

SI

watt_hour

Wh

standard *

watt_hours

SI

ton

 

TNT

tons

SI

 

 

 

 

 

calorie

cal

thermochemical *

calory, calories

SI

 

 

IT

 

 

 

 

mean

 

 

 

 

`15degC`

 

 

 

 

`20degC`

 

 

 

 

 

 

 

Calorie

Cal

thermochemical *

Calories

 

 

 

IT

 

 

 

 

mean

 

 

 

 

`15degC`

 

 

 

 

`20degC`

 

 

 

 

 

 

 

British_thermal_unit

Btu

thermochemical *

British_thermal_units

 

 

 

IT

 

 

 

 

mean

 

 

 

 

`39degF`

 

 

 

 

`59degF`

 

 

 

 

`60degF`

 

 

 

 

 

 

 

therm

te

thermochemical *

therms

SI

 

 

IT

 

SI

 

 

mean

 

SI

 

 

EU

 

SI

 

 

US

 

SI

 

 

 

 

 

quad

 

thermochemical *

quads

 

 

 

IT

 

 

 

 

mean

 

 

 

 

 

 

 

Q_unit

 

thermochemical *

Q_units

 

 

 

IT

 

 

 

 

mean

 

 

 

 

 

 

 

Celsius_heat_unit

Chu

thermochemical *

Celsius_heat_units

 

 

 

IT

 

 

 

 

mean

 

 

 

 

`15degC`

 

 

 

 

`20degC`

 

 

 

 

 

 

 

planck_energy

 

planck *

planck_energies

 

  

An asterisk ( * ) indicates the default context, an at sign (@) indicates an abbreviation, and under the prefixes column, SI indicates that the unit takes all SI prefixes, IEC indicates that the unit takes IEC prefixes, and SI+ and SI- indicate that the unit takes only positive and negative SI prefixes, respectively.  Refer to a unit in the Units package by indexing the name or symbol with the context, for example, joule[SI] or Cal[thermodynamic]; or, if the context is indicated as the default, by using only the unit name or symbol, for example, joule or Cal.

  

 

  

The units of energy are defined as follows.

  

An electron volt is defined as 1.6021773310-19 joule, that is, the product of the charge of an electron in coulombs with a joule per coulomb.

  

An erg is defined as 1.10-7 joule.

  

A watt hour is defined as 3600 joules.

  

A ton of nuclear equivalent TNT is equal to 1.109 thermochemical calories.

  

An EU therm is defined as 105506000 joules.

  

A US therm is defined as 105480400 joules.

  

A planck energy is defined as a planck mass times planck length squared per planck time squared.

The Calorie

• 

For each context of the calorie, there exists a unit, the Calorie, that is by definition 1000 times the value. Therefore, a Calorie is a kilocalorie.

  

A 15 degree Celsius or 20 degree Celsius calorie is approximately the amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius to 15.5 or 20.5 degrees Celsius, respectively.

  

A thermochemical calorie is defined as 4.184 joules.

  

A International Table calorie is defined as 4.1868 joules.

  

A mean calorie is 1100 the energy required to raise the temperature of 1 gram of water from 0 degrees Celsius to 100 degrees Celsius, and is approximately 4.19002 joules.

British Thermal Units

  

A 39 degree Fahrenheit, 59 degree Fahrenheit, or 60 degree Fahrenheit calorie is the approximate amount of energy required to raise the temperature of 1 pound of water by 1 degree Fahrenheit to 39.5, 59.5, or 60.5 degrees Fahrenheit, respectively.

  

A thermochemical British thermal unit is defined by the relationship: 1 thermochemical British thermal unit per pound degree Fahrenheit equals 1 thermochemical kilocalorie per kilogram kelvin.

  

A International Table British thermal unit is defined by the relationship: 1 International Table British thermal unit per pound degree Fahrenheit equals 1 International Table kilocalorie per kilogram kelvin.

  

A mean British thermal unit is 1180 the energy required to raise the temperature of 1 pound of water from 32 degrees Fahrenheit to 212 degrees Fahrenheit.

  

 

• 

For the thermochemical, International Table, and mean contexts, there are the following associated units.

  

A therm is defined as 10000. British thermal units.

  

A quad is defined as 1.1015 British thermal units.

  

A Q unit is defined as 1.1018 British thermal units.

Celsius Heat Units

  

A 15 degree Celsius or 20 degree Celsius heat unit is the approximate amount of energy required to raise the temperature of 1 pound of water by 1 degree Celsius to 15.5 or 20.5 degrees Celsius, respectively.

  

A International Table Celsius heat unit is defined by the relationship: 1 International Table Celsius heat unit per pound equals 1 International Table kilocalorie per kilogram.

  

A thermochemical Celsius heat unit is defined by the relationship: 1 thermochemical Celsius heat unit per pound equals 1 thermochemical kilocalorie per kilogram.

  

A mean Celsius heat unit is 1100 the energy required to raise the temperature of 1 pound of water from 0 degrees Celsius to 100 degrees Celsius.

Examples

convert'J','dimensions','base'=true

length2masstime2

(1)

convert1,'units','J','kilowatt''hour'

13600000

(2)

convert1,'units','J','Btu'

2250000023722880951

(3)

convert1.0,'units','cal','BtuIT'

0.003965666831

(4)

convert1.0,'units','calIT','BtuIT'

0.003968320719

(5)

convert325,'units','J','thermUS'

134219216

(6)

convert325,'units','J','thermEU'

134220240

(7)

convert22000,'units','Q_unitthermochemical','tonTNT'

498951607000000009

(8)

See Also

convert/dimensions

convert/units

Units

Units/Index

Units/length

Units/mass

Units/time

 


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