Análogo mecânico para a discussão de conceitos da Termodinâmica

Abstract

Teaching physics in basic education, in addition to providing a scientific basis for students to study nature, is very important to present to them career opportunities in science, technology, engineering, medicine, among others. Therefore, questions about an optimized method for teaching and learning physics have been insistently asked by both experienced and inexperienced teachers and researchers as well as by students preparing to be a teacher. A universal answer to these questions is practically impossible to provide, owing the different teaching objectives and conditions of each school or region, which are changing dynamically. There are countless approaches and directions that can be taken and probably the “best way” to teach any discipline does not exist. For effective teaching and learning it is necessary to take into consideration several factors such as the teacher, students' prior knowledge, age, the infrastructure and the school curriculum, among others. In this work we approach the teaching of thermodynamics using analogies, through the guide structure of the “Teaching With Analogies” (TWA) model, from an experiment composed of communicating vessels and some accessories to simulate thermodynamic systems in thermal contact. This approach enables us to discuss in more detail concepts such as temperature, heat, energy, work, thermal capacity and their relationship with the Zeroth, the First and the Second Laws of Thermodynamics. The proposal was applied in a private school in the interior of São Paulo for 40 students attending junior and senior years of high school in four classes of forty-five minutes duration. Our didactic sequence was divided into 3 activities, the first focusing on mapping the students' previous knowledge through an opinion survey, the second for presenting and executing the experiment, covering all the proposed topics using the analogies, and in the third an essay questionnaire was provided for the students write about the subject addressed. We concluded that the application of our proposal was successful. By using analogies we established more coherent discussions with the physical and scientific reality of the studied systems, providing greater interaction between the teacher and the students and among students. The students also carried out the activities with greater engagement and motivation. Our educational product is composed by the communicating vessels experiment and a suggestion of how to approach the thermodynamic concepts using the proposed analogies, in an attempt to better clarify mainly the difference among the concepts of heat, temperature and energy, so that they can be defined and used in the students' daily lives more appropriately.