Glossary letter J


A derived unit of energy, work or amount of heat in the International System of Units. Its symbol is J. The kilowatt-hour is more common in the fields of electric power and thermal energy (1 kWh = 3,600 kJ) and the calorie in nutrition (1 cal = 4.18 J). A joule is defined as the energy expended (or work done) in applying a force of one newton through a distance of one meter.