Heat and Temperature | Differences
The difference between heat and temperature is that heat is defined as the movement or exchange of energy between bodies, while temperature is the measure of the agitation of the molecules of a body.
The relationship between heat and temperature is that for the temperature of a body to change there must be a transfer of heat.
|Transfer of energy from one body to another.
|Measurement of the kinetic energy of the molecules of a material.
|A hot spoon transfers heat to the cold water in a cup.
What is Heat?
The definition of heat in physics is the transfer of thermal energy that flows from a body with a higher temperature to another with a lower temperature. Thermal equilibrium is reached when the temperature between both bodies is the same. In physics there is no such concept as “the amount of heat in a body“.
Heat transmission can occur in the following ways:
- Thermal Conduction: the heat transfer is given by the agitation of molecules that causes the rise in temperatures, the expansion of bodies, the melting of solids and the evaporation of liquids.
- Thermal Convection: heat transfer occurs between liquids and gases. For example: when boiling water.
- Thermal Radiation: heat is propagated by electromagnetic waves without the need for both bodies to have contact.
In the International System of Units (ISU), heat is measured in units of energy joules (J). It can also be measured in calories, where 1 calorie = 4.186 joules. The calorimetry is the part of physics that heat, ie, the energy transfer from one body to another.
What is Temperature?
Temperature is the physical quantity that measures the kinetic energy of molecules and the thermal state of a body. That is, the hotter the body, the greater its molecular agitation, on the contrary, the colder the body, the less its molecular agitation.
The thermometer is the device used to measure temperature, whose value can be presented on thermometric scales:
- Celsius (° C),
- kelvin (K) or
- Fahrenheit (° F).
On the Kelvin scale, the melting point of water is 273 K (0 ° C), and the boiling point is 373 K (100 ° C). On the Fahrenheit scale, the melting point of water is 32 ° F (0 ° C) and the boiling point is 212 ° F (100 ° C).