# Laws of Thermodynamics

The laws of thermodynamics describe the specifics for the transport of heat and work in thermodynamic processes. Since their conception, these laws have become some of the most important in all of physics and other branches of science connected to thermodynamics. They are often associated with concepts far beyond what is directly stated in the wording.

## First Law of Thermodynamics

The definition of the first law of thermodynamics is the conversion of energy in a thermodynamic system; the total energy of a system can be increased by doing work on it or by adding heat.

The equation is: ΔW+ΔQ = (ΔKE+ΔPE+ΔTE) .

Where W is work, Q is heat, KE is kinetic energy, PE is potential energy, and TE is thermal energy.

Heat is the energy transferred as a result of a temperature difference between two objects.

## Second Law of Thermodynamics

The second law of thermodynamics states that for any spontaneous process, the entropy of an isolated system can only increase or stay the same, but never decrease. Entropy is used to measure the disorder of a system. Heat can flow spontaneously, by itself, only from a hot source to a cold sink. No heat engine can be constructed in which heat from a hot source is converted entirely to work. The equation is

Efficiency = (heat in - heat out/ heat in) x 100% = (1 - heat out/heat in) x 100%