Thermodynamics adds a new quantity, called internal energy, into the fold; it’s the energy possessed by the system itself. Getty Images If we add heat to the system, its internal energy increases.

The fundamental principles of thermodynamics are expressed in four laws. "The First Law says that the internal energy of a system has to be equal to the work that is being done on the system ...

The energy of a thermodynamic system that is NOT either the kinetic energy or gravitational potential energy of the system as a whole is known as Internal Energy. The internal energy is associated ...

The amount of energy in the universe is constant and can neither be destroyed nor created, that's what the first law of thermodynamics ... which is the sum of its internal energy combined with ...