How to Deal with the Concept of Mechanical Energy in Dissipative Systems? A Study on Conceptual Development of First-Year University Students in Mozambique

Abstract

The study aimed (a) to describe conceptions about energy of first-year university students in Mozambique, and (b) to determine the impact of a conceptual development approach to the students’ conceptions of mechanical energy. Initially students appear to have difficulties with the concept of potential energy and to strongly defend the conservation of mechanical energy in dissipative systems. The instruction started from students’ conceptions, and analysed processes of energy transfer by defining the system to be focused on, searching for differences between the states before and after a process. Degradation of energy was discussed and explained first, before the teaching started to focus on conservation of energy. Improvements were found in posttest scores and post-interviews.