Energy, work and amount of heat share the same dimensions. While expression in a coherent unit is preferred, reference to older units may still be encountered.
Coherent Units
|
Units |
System |
Symbol |
Joules |
|
joule (newton•meter, Watt•sec) |
SIU |
J |
1 |
|
erg (dyne•cm) |
CGS |
erg |
10^(-7) |
|
foot poundal |
ft-lb-s |
ft pdl |
0.042140 |
where:
• Joule = m^2 • kg • s^(-2)
• erg = cm^2 • g • s^(-2)
• foot poundal = ft^2 • lb • s^(-2)
Noncoherent Units
|
Units |
Symbol |
Joules |
|
foot pound-force |
ft lbf |
1.35582 |
|
calorie, thermochemical |
cal (thermochem) |
4.184 |
|
calorie, 15°C |
cal (15) |
4.1855 |
|
calorie, International Steam Table |
cal (IT) |
4.1868 |
|
kilopod metre (kilogram-force metre) |
kp m = kgf m |
9.80665 |
|
litre atmosphere |
l atm |
1.01325 * 10^2 |
|
British thermal unit |
Btu |
1.05506 * 10^3 |
|
horsepower-hour |
hph |
2.68452 * 10^6 |
|
metric horsepower-hour |
ch |
2.64780 * 10^6 |
|
kilowatt hour |
kWh |
3.6 * 10^6 |
where:
• 1 calorie at 15°C is the amount of energy required to increase the temperature of 1 gram of water from 14.5 to 15.5°C at 1 standard atmosphere pressure. 1 Calorie = 1,000 calories = 1 kcal.
Implementation: Convert input units to joules, then from joules to the output units.
