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Specific heat ratio k is defined as the ratio Cp/Cv

Specific heats for solids and liquids, or incompressible substances, are equal.

Specific properties are extensive properties per unit mass. Some examples of specific
properties are specific volume (v=V/m) and specific total energy (e= E/m).

State is the condition of a system not undergoing any change gives a set of properties
that completely describes the condition of that system. At this point, all the properties
can be measured or calculated throughout the entire system.

Steady implies no change with time. The opposite of steady is unsteady, or transient.

Surroundings are everything outside the system boundaries.

Thermal efficiency η th is the ratio of the net work produced by a heat engine to the total
heat input, η th = W net /Q in

Thermodynamics can be defined as the science of energy. Energy can be viewed as the
ability to cause changes. The name thermodynamics stems from the Greek words
therme (heat) and dynamis (power), which is most descriptive of the early efforts to
convert heat into power. Today the same name is broadly interpreted to include all
aspects of energy and energy transformations, including power production,
refrigeration, and relationships
among the properties of matter.

Unsteady-flow, or transient-flow, processes are processes that involve changes within a
control volume with time.

Work is the energy transfer associated with a force acting through a distance.

Working fluid is the fluid to and from which heat and work is transferred while
undergoing a cycle in heat engines and other cyclic devices.

Zeroth law of thermodynamics states that if two bodies are in thermal equilibrium with
a third body, they are also in thermal equilibrium with each other.

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