This small group activity is designed to help students with difficult aspects of thermodynamic cycles, especially their purpose, how they work, and the nature of state variables when a full cycle is completed.
Students work in small groups to explore concepts related to cycles using the Partial Derivative Machine to envision an elevator that must be loaded, raised, unloaded, and then returned to the initial level, as a means to build a productive analogue to thermodynamic cycles such as heat engines.
The whole class wrap-up discussion emphasizes the deep connections between the Partial Derivative Machine system and thermodynamic systems such as a gas in a piston.
Students are often confused about how a thermodynamic cycle actually connects to a real world system. Since the Partial Derivative Machine is a more visible and tangible system than something like a gas in a piston, it is easier for students to make conceptual connections between the physical setup and the graphs, equations, and calculations used to describe a cycle. Students can then use this understanding as a bridge to more complicated thermodynamic systems using PDM vocabulary built in previous activities.