Second Law Redux

Abstract

Classical thermodynamics, as usually presented to engineering students, offers a midcourse impediment known as the Second Law. The Second Law suffers from a lack of intuitive clarity. The objective of the present work is to provide clarity, for simple systems to aid students and teachers. In this effort, it is demonstrated that Planck’s statement of the Second Law can be viewed as a corollary of a more fundamental observation, namely that work must always be done against friction. Also, Clausius's statement is demonstrated, entropy is defined, and Caratheodory’s statement is validated.