First Principle: General Statement

This lecture introduces the first principle of thermodynamics, which states that for any system, there is a scalar and extensive state function called energy. If the system is isolated, then the energy is conserved. The lecture covers the distinction between isolated and non-isolated systems, as well as the impact of external processes, forces, and moments on the energy of a system. Definitions of powers related to mechanical, thermal, radiation, and chemical processes are discussed, along with the effects of external forces and moments on the state of motion of a system.