Temperature is a marker of the ‘hotness’ of a body. It determines the direction of flow of heat when two bodies are placed in thermal contact. Heat flows from the body at a higher temperature to the one at lower temperature. The flow stops when the temperatures equalise; the two bodies are then in thermal equilibrium.
Internal energy is simply the sum of the kinetic energies and potential energies of these molecules. Internal energy is thus, the sum of molecular kinetic and potential energies in the frame of reference relative to which the centre of mass of the system is at rest. Thus, it includes only the (disordered) energy associated with the random motion of molecules of the system.and is denoted by U.
internal energy is depends only on the state of the system, not on how that state was achieved. Internal energy U of a system is an example of a thermodynamic ‘state variable’.Its value depends only on the given state of the system, not on history i.e. not on the ‘path’ taken to arrive
at that state. Thus, the internal energy of a given mass of gas depends on its state described by specific values of pressure, volume and temperature.
It does not depend on how this state of the gas came about. Pressure, volume, temperature, and internal energy are thermodynamic state variables of the system .The internal energy of a gas is just the sum of kinetic energies associated with various random motions of its molecules.It also includes rotational and vibrational motion of the molecules.
Heat and work are two different modes of altering the state of a thermodynamic system and changing its internal energy. Heat is certainly energy, but it is the energy in transit.Heat and work in thermodynamics are not state variables. They are modes of energy transfer to a system
resulting in change in its internal energy.
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Internal energy is simply the sum of the kinetic energies and potential energies of these molecules. Internal energy is thus, the sum of molecular kinetic and potential energies in the frame of reference relative to which the centre of mass of the system is at rest. Thus, it includes only the (disordered) energy associated with the random motion of molecules of the system.and is denoted by U.
internal energy is depends only on the state of the system, not on how that state was achieved. Internal energy U of a system is an example of a thermodynamic ‘state variable’.Its value depends only on the given state of the system, not on history i.e. not on the ‘path’ taken to arrive
at that state. Thus, the internal energy of a given mass of gas depends on its state described by specific values of pressure, volume and temperature.
It does not depend on how this state of the gas came about. Pressure, volume, temperature, and internal energy are thermodynamic state variables of the system .The internal energy of a gas is just the sum of kinetic energies associated with various random motions of its molecules.It also includes rotational and vibrational motion of the molecules.
Heat and work are two different modes of altering the state of a thermodynamic system and changing its internal energy. Heat is certainly energy, but it is the energy in transit.Heat and work in thermodynamics are not state variables. They are modes of energy transfer to a system
resulting in change in its internal energy.
Related Posts
Zeroth law of thermodynamics
Thermodynamics Introduction
Heat transfer by radiation
Heat transfer by convection
Heat transfer and conduction
Heat and Temperature
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