Graphic Representation of Quasi-Static Heat Exchange

Abstract

Two bodies initially at different temperatures gathered into an isolated container exchange heat and reach an equilibrium state with a common final temperature. During the process, the system is out of equilibrium and its intermediate temperature is not well defined. By conceiving a quasi-static process with infinitesimal steps from the initial to the final state, a graphic representation of the intermediate temperatures is possible. We imagine an isolated container with the bodies in compartments separated by a wall, as shown in Fig. 1. If the conductivity of the wall is controlled, the heat exchange is made gradually through a sequence of very small portions of heat flowing from one body to the other. Each step is followed by a “dead time” in order to reach a momentary equilibrium state. These graphs are useful for students who need to analyze a phase change.

Representation and content in student's exam note sheets

“…Many studies show that the use of various representations such as verbal, mathematical equations, graphs and diagrams will deepen students' understanding. The graphic and visual representation have been used in teaching heat, astronomy, particle physics (Rojas & Robles, 2018;Wallace et al, 2016;Wiener et al, 2017). Multiple representations i.e.…”