Research continuously shows that interest, motivation, and engagement in learning physics decline with years of schooling. Some research show that the decline in interest in learning physics begins at the beginning of formal education in physics, so the aim of this research was to examine the determinants of motivation and engagement in learning of students who are just encountering the subject of physics. Engagement in learning is an objective manifestation of motivation, and according to most authors, it consists of behavioural (attention, concentration, and perseverance), cognitive (learning with understanding) and emotional (positive emotions during learning) aspects. According to the contextual model of school engagement, students’ motivational beliefs mediate the relationship between contextual factors and engagement in learning. Structural equation modelling was used to test the mediating role of students’ motivational beliefs (self-efficacy, interest, utility, and attainment) in the relationship between three aspects of the teacher’s motivating style (involvement, autonomy, and structure) and three aspects of engagement in learning physic (behavioural, cognitive, and emotional). The participants were 595 7th-grade students from ten elementary schools in Zagreb with an average age of 13 (51% girls). The results of the research are in line with the theoretical model, and they showed that the most important mediator was the interest in physics that mediated the relationship between teacher involvement and structure and behavioural and emotional engagement in learning physics. Self-efficacy beliefs and utility mediated the relationship between teacher provision of autonomy and cognitive engagement in physics. The results have theoretical and practical implications.
