In classical thermodynamics the term ‘heat’ is used to describe the energy transfer that occurs between a system and its surroundings when a temperature difference exists between them. It follows that heat transfer can only take place across the boundary of a system. Thermodynamics is able to describe the direction of the heat transfer across the boundary and the total mount of energy transferred in this way, but not the rate at which the transfer takes place.
Unable to display preview. Download preview PDF.