# joule (J)

The joule (J) is a derived unit of energy in the SI system of units. It is named
after the English physicist James Joule. 1
joule is the energy used (or the work done)
by a force of one newton in moving its point of application one meter in the direction of the force; also equivalent to the energy dissipated
by 1 watt in one second, it equals 10^{7} erg in CGS units. In older units, 1 Btu
= 1,055 joules; 1 joule per second = 0.737 ft-lb/s.

One joule is also the work done when a one ampere current is passed through a resistance of one ohm for one second.