Relations between work and energy are still a source of teaching-learning problems in the first years of university introductory physics courses since they involve abstract concepts and skills of scientific methodology. Considering the previous studies in the literature, the main objective of this contribution is to identify and document specific difficulties that students show while thinking and reasoning about the relation between work and energy in isolated systems. This research consists in the analysis of answers to a work-energy questionnaire administered to students taking introductory physics courses at the University of the Basque Country (Spain). The results of four questions presented to the students show that, after the instruction, students still have problems calculating the scalar product in the definition of work, and that a good portion of students have difficulties in establishing correct relations between the work done by an external force to the system and the energy variation of the system. At the end, general conclusions of this contribution are established where recommendations are made to the instructor and researcher.
Keywords:
physics education research at university; General Principle on work and energy; work; students' learning