internal energy

noun, Thermodynamics
1.
a function of thermodynamic variables, as temperature, that represents the internal state of a system that is due to the energies of the molecular constituents of the system. The change in internal energy during a process is equal to the net heat entering the system minus the net work done by the system. Symbol: U.
Origin
1885-90
Examples from the web for internal energy
  • The amount of internal energy and the means of dissipation are dependent on the size of the planet.
  • Methane is a gas that absorbs light from the sun and increases it's internal energy, creating heat.
  • Since the internal energy is a function of both temperature and pressure, it's difficult to give an answer to your question.
  • The city has established an internal energy efficiency award to recognize divisions that improve energy efficiency.
  • By allowing gases to expand, the gas is doing work and therefore losing internal energy.
  • The plasma should have collapsed, its internal energy radiated away.
  • The photon is then either scattered without altering the internal energy of the atom, or it is fully absorbed.
  • Mechanical energy is also removed and converted into internal energy through frictional dissipation.
British Dictionary definitions for internal energy

internal energy

noun
1.
the thermodynamic property of a system that changes by an amount equal to the work done on the system when it suffers an adiabatic change. It is the sum of the kinetic and potential energies of its constituent atoms, molecules, etc U, E
Encyclopedia Article for internal energy

in thermodynamics, the property or state function that defines the energy of a substance in the absence of effects due to capillarity and external electric, magnetic, and other fields. Like any other state function, the value of the energy depends upon the state of the substance and not upon the nature of the processes by which it attained that state. In accordance with the first law of thermodynamics, when a system undergoes a change of state as a result of a process in which only work is involved, the work is equal to the change in internal energy. The law also implies that if both heat and work are involved in the change of state of a system, then the change in internal energy is equal to the heat supplied to the system minus the work done by the system

Learn more about internal energy with a free trial on Britannica.com