| Revision as of 16:53, 31 August 2003 editTarquin (talk | contribs)14,993 editsmNo edit summary← Previous edit | Revision as of 09:27, 2 October 2003 edit undo193.2.69.128 (talk) +sl:Next edit → | ||
| Line 2: | Line 2: | ||
| ] | ] | ||
| ] | ] | ||
| ] | |||
| The '''joule''' (J) is the ] unit of ] and ], and is defined as 1 ] ]<sup>2</sup> ]<sup>-2</sup> = 1 ] ] = 1 ] ]. It is named in honour of the physicist ]. | The '''joule''' (J) is the ] unit of ] and ], and is defined as 1 ] ]<sup>2</sup> ]<sup>-2</sup> = 1 ] ] = 1 ] ]. It is named in honour of the physicist ]. | ||
Revision as of 09:27, 2 October 2003
The joule (J) is the SI unit of energy and work, and is defined as 1 kg m s = 1 N m = 1 W s. It is named in honour of the physicist James Prescott Joule.
One joule is the work required to exert a force of 1 Newton for a distance of 1 metre, so the same quantity may be referred to as a newton metre. That is the work required to lift a mass of 102 g (e.g. a small apple) for one metre under the earth's gravity.
One joule is also the work done to produce power of 1 watt for 1 second, such as when somebody takes 1 second to lift the small apple mentioned above through 1 metre under the earth's gravity.
1 joule is equal to:
- 0.000,000,278 Kilowatt-hours
- 0.239 calories
- 0.000,948 British thermal units
- 0.738 foot pounds force
- 1 Ws (Watt second)
- 1 Nm (Newton metre)
- 23.7 foot poundals
- 10,000,000 ergs
See 1 E0 J for further comparisons.
See also: conversion of units, eV, kWh, TWh