Interpretation of Graphical Information in PV Graphics

Thermodynamic processes are often presented in so called P-V diagrams and the processes are often isobaric, isochoric, isothermal, and adiabatic. The purpose of the qualitative research reported here was to explore students' reasoning and interpretation of P-V diagrams that were presented by the help of GeoGebra. The research group had 15 students and the control group had 12 students. The control group were not given any dynamical explanation of the PV diagrams but were taught with static images in the same text book as the research group. The thermodynamics in Physics 1 at the Swedish gymnasium level is normally done within 2 weeks. We allocated 3 weeks and 10 hours for the thermodynamics to be taught and then gave all 27 students a short test. At the end of the Physics 1 course, we also gave a test with two questions from the thermodynamics. It seems that the students who were given the opportunity to dynamically change the content of the PV diagram benefit more from the teaching compared to the control group.