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The joule (/ˈl/ or whiles /ˈl/), seembol J, is a derived unit o energy, wirk, or amoont o heat in the Internaitional Seestem o Units.[1] It is equal tae the energy expendit (or wirk duin) in applyin a force o ane newton throu a distance o ane metre (1 newton metre or N·m), or in passin an electric current o ane ampere throu a resistance o ane ohm for ane seicont. It is named efter the Inglis pheesicist James Prescott Joule (1818–1889).[2][3][4]

Unit seestem SI derived unit
Unit o Energy
Seembol J 
Named efter James Prescott Joule
Unit conversions
1 J in ...... is equal tae ...
   SI base units    1 kg·m2/s2
   CGS units    1×107 erg
   kilowatt hours    2.78×10−7 kW⋅h
   kilocalories    2.39×10−4 kcal
   BTUs    9.48×10−4 BTU
   electronvolts    6.24×1018 eV


  1. International Bureau of Weights and Measures (2006), The International System of Units (SI) (PDF) (8th ed.), p. 120, ISBN 92-822-2213-6 
  2. American Heritage Dictionary of the English Language, Online Edition (2009). Houghton Mifflin Co., hosted by Yahoo! Education.
  3. The American Heritage Dictionary, Second College Edition (1985). Boston: Houghton Mifflin Co., p. 691.
  4. McGraw-Hill Dictionary of Physics, Fifth Edition (1997). McGraw-Hill, Inc., p. 224.