L3 slide 12: Entropy of an isolated two-body system (ENGR5003)

L3 slide 12: Entropy of an isolated two-body systemFrom lectureCurrent specThird2 marks3 min

ENGR5003 Lecture 3, slide 12 (Increase of entropy principle for isolated system)

An isolated system consists of two bodies at different temperatures that are placed in thermal contact. Heat flows between them until they reach thermal equilibrium. What happens to the total entropy of the isolated system?

Formulas you may need

Increase of entropy principle: $\Delta S_{iso} = S_g \ge 0$ (on the formula sheet)
Entropy change of a body: $dS = \delta Q/T$ (on the formula sheet)

AIt decreasesBIt remains constantCIt increasesDIt becomes zero