Joule

About Joule

The joule (written in lower case, pronounced /ˈdʒuːl/ or /ˈdʒaʊl/) (symbol: J) is the SI unit of energy measuring heat, electricity and mechanical work. It was named after English physicist James Prescott Joule.

One joule is the work done, or energy expended, by a force of one newton moving one metre along the direction of the force. This quantity is also denoted as a newton metre with the symbol N·m. Note that torque also has the same units as work, but the quantities are not the same. In elementary units: