joule

The joule (J) is an SI (derived) unit of energy equivalent to the work done by the force of a newton (a unit of force) pushing over a meter distance. A joule is one kilogram meter-squared per second-squared (kg·m²/s²), a newton being the force necessary to accelerate a kilogram one meter per second-squared. This is very roughly the energy to lift (in Earth surface gravity) a pound weight 9 inches, or a kg weight 10 cm. A joule is also a watt-second. 10⁷ ergs make a joule.