Energy Transferred by Working
Energy and Thermal Physics


Physics Narrative for 11-14 Supporting Physics Teaching

Standard and not so standard units

The standard unit for energy is the joule, but not all energies are quoted in joules. There is therefore a very real chance that you will come across data in awkward units. If you need to perform conversions, the following tables should help.

Energy conversion table

energy unitequivalent
joule1 J
kilojoule1000 J
megajoule1 000 000 J
gigajoule1 000 000 000 J
terajoule1 000 000 000 000 J
Btu1055 J
therm105 500 000 J
gallon of petrol131 000 000 J
barrel of petrol5 498 000 000 J
barrel of crude oil6 119 000 000 J
ton of coal21 896 000 000 J
million cubic feet of natural gas1 083 000 000 000 J
calorie4.1868 J
kilocalorie4186.8 J
kilowatt-hour3 600 000 J

Power conversion table

1 Btu per hour0.293 W
1 joule per second1 W
1 kilowatt hour per day41.7 W
1 food calorie per minute69.77 W
1 horsepower745.7 W
1 kilowatt1000 W
1 Btu per second1054 W
1 gallon of gasoline per hour39 kW
1 million barrels of oil per day73 GW
Energy Transferred by Working
appears in the relation dU=dQ+dW
is used in analyses relating to Working Engines Thermionic Emission
is a special case of Work
has the special case Potential Energy Kinetic Energy
2023 IOP Awards

Teachers of Physics Awards

Recognising and celebrating outstanding contributions to the field of physics education.

Learn more