This article addresses a case study related to the relationship between teacher mediation and students' epistemic practices in the teaching-learning process of projectile movement modeled by computer simulations. It started from the following question: what implications do the convergences and/or divergences of teacher mediation practices have on students' epistemic practices, in the particular case of similarities in teaching contexts, teaching-learning task design and computer simulator? However, its relevance lies in the identification of students' epistemic practices that are independent and/or dependent on the characteristics of teacher mediation, teaching context and mediating artifacts; hence, the study aimed to identify the epistemic practices mobilized by students from two schools during a class on the movement of a projectile modeled by computer simulations, as well as to understand the relationships between such practices and the characteristics of the mediation used by the respective teachers. The study focused on first-year undergraduate students in Physics Education from two institutions in Angola, the Instituto Superior de Ciências de Educação do Uíge (ISCED-Uíge) and the Escola Superior Pedagógica de Ndalatando (ESPN) in the academic year 2024-2025. The study started with the application of a pre-test, following the joint planning of a teaching session by both teachers, which maintained common characteristics regarding objectives, task design and mediating artifact, both using the Physics Education Technology (PhET) simulator. The next phase consisted of the intervention of both teachers in the classroom at their respective institutions, which favored the application of the post-test in the following session. Despite the application of two tests, data were also collected from within the classroom on the interactions between subjects around the epistemic object through audio, video and photographic recordings of the students' productions throughout the class. The analysis of these data was carried out through Discursive Textual Analysis (DTA), which led to their triangulation through the various sources of evidence used, thus allowing us to conclude that there are epistemic practices that are independent and dependent on teacher mediation in teaching-learning shaped by computer simulations; a situation that opens up new perspectives in the sense of expanding this study to other areas of physics, as well as in the aspect of identifying the effectiveness of the dependent and independent characteristics of teacher mediation on students' epistemic practices.

Keywords: Computer Simulations, Teaching Mediation, Students, Epistemic Practices, Projectile Movement.