The joule (symbol: J) is the SI unit of energy, work, or heat. It is defined as the amount of energy transferred when a force of one newton is applied over a distance of one meter. The formal definition can be expressed as:
1 joule = 1 newton × 1 meter
Mathematically, this can be written as:
1 J = 1 N·m
Where:
- 1 newton (N) is defined as the force required to accelerate a mass of one kilogram at a rate of one meter per second squared (1 N = 1 kg·m/s²).
Thus, one joule is also equivalent to:
1 J = 1 kg·m²/s²
This definition encompasses various forms of energy, including kinetic energy, potential energy, and thermal energy.