Second Law of Thermodynamics

The second law of thermodynamics (entropy) states that heat cannot pass from a cold body to a hot one by a self-acting process without the help of an external influence.  Entropy is the measure of disorder within a system. The more disorder within the system, energy becomes less available to do work.

 

Second Law of Thermodynamics formula

\(\large{ \Delta S = \frac {\Delta Q} {T}   }\)

Where:

Units	English	Metric
\(\large{ \Delta S }\) = entropy differential	\(\large{\frac{Btu}{lbm-R}}\)	\(\large{\frac{kJ}{kg-K}}\)
\(\large{ \Delta Q }\) = heat differential (energy)	\(\large{\frac{Btu}{lbm}}\)	\(\large{\frac{J}{kg}}\)
\(\large{ T }\) = temperature	\(\large{R}\)	\(\large{K}\)