Application of the Second Law of Thermodynamics To Explain the Working of Toys.

This teaching activity consists of challenging students to explain the working principle behind three scientific toys: a drinking bird, a radiometer, and a Stirling engine. The transformation of heat (q, thermal energy generated by a temperature difference) into work (w, mechanical energy manifested as motion) is implicit in the working of these toys. Such a transformation constitutes a central argument in the conceptual and historical development of entropy (S) and of the second law of thermodynamics (SLT). The observation and the understanding of the common working principles of these toys promoted a positive reaction by students toward the formal development of a conceptual understanding of the SLT and the concept of entropy. [ABSTRACT FROM AUTHOR]