Work is the energy required to move an object against a force. Work is equal to the force times the distance the object moves. The SI unit for work is the joule.

Work and heat can both be described using the same unit of measure. Sometimes the calorie is the unit of measure, and refers to the amount of heat required to raise one (1) gram of water one (1) degree Celsius. Heat energy is measured in kilocalories, or 1000 calories. Typically, we use the SI units of Joules (J) and kilojoules (kJ).

One calorie of heat is equivalent to 4.187 Joule. We will also encounter the term specific heat, the heat required to raise one (1) gram of a material one (1) degree Celsius. Specific heat, given by the symbol "C", is generally defined as:

C = q / MT


C = specific heat in cal/g-°C

q = heat added in calories,

m = mass in grams

T = rise in temperature of the material in °C.