Thermodynamics. Justify that it is the science to calculate energy, energy and entropy.

Sol : Thermodynamics is science which deals with conversion of heat into mechanical energy. It is  based upon observations of general experience, that have been formulated into thermodynamic laws. These laws govern principles of energy conversion. The applications of thermodynamic laws and principles are found in all the fields of energy technology, especially in steam and nuclear power plants, air conditioning, gas turbines, refrigeration, gas dynamics, internal combustion engines jet propulsion, chemical process plants, compressors, and direct energy conversion devices.

In general thermodynamics contains four laws;

1. Zeroth law: it deals with thermal equilibrium and establishes concept of temperature.

2. The First law: throws introduces the concept of internal energy.

3. The Second law: indicates limit of converting heat into work and introduces the principle of increase of entropy.

4. Third law: defines absolute zero of entropy.

These laws are based on experimental observations and have no mathematical proof. Similar to all the physical laws, these laws are based on logical reasoning.

Thermodynamics is study of energy, energy and entropy.

The entire heat energy cannot be converted into mechanical energy by machine. Some portion of heat at low temperature has to be librated to the environment.

The portion of heat energy, that is not available for conversion into work, can be measured by entropy. The part of heat, that is available for conversion into work, is called as energy.

Hence, thermodynamics is science, which calculates energy, energy and entropy.