Question

Why is the joule, the SI unit of energy, also the appropriate unit for measuring heat?

Answer 1

The standard unit for the rate of heat transferred is the watt (W), defined as one joule per second. In CGS system, heat is measured in calories. Calorie is defined as 'the heat energy required to increase the temperature of 1 gm of water through one degree Celsius'. In SI system, heat energy is measured in joules (J).