The connection between macroscopic nonconservative forces and microscopic conservative forces is described by detailed treatment with statistical mechanics. In macroscopic closed systems, nonconservative forces act to change the internal energies of the system, and are often associated with the transfer of heat. According to the Second law of thermodynamics, nonconservative forces necessarily result in energy transformations within closed systems from ordered to more random conditions as entropy increases.
In what treatment are nonconservative and conservative forces described? What changes macroscopic closed system energies? What is the exchange of heat associated with? What is the law of thermodynamics associated with closed system heat exchange? What makes energy changes in a closed system?