Estudo dos gases, do ponto de vista cinético, com o auxílio de um simulador mecânico

Abstract

Among the scientific achievements that gave us a better understanding of the constituents of nature, we can mention the development of the kinetic theory of gases and Einstein's work on Brownian motion, which convinced scientists to believe in the existence of atoms and molecules. As this model is still little explored in elementary school, we see the need to present the concept of Brownian motion to high school students that will serve as a starting point for students to understand that matter, particularly fluids, are made up of atoms and molecules in constant random motion, and that these have kinetic energy, which leads to a new interpretation of the concepts of temperature, pressure and volume. With this aim in view, this work aims to offer a proposal for the construction and application in the classroom of an educational product constituted by a mechanical model called Mechanical Simulator of Vibrational Motion (SMMV). This model consists of an amplifier, a sound box, cylindrical plastic containers, table tennis balls, styrofoam balls and "party" balloon. The chaotic movements of the balls and balloon in the simulator will represent the movements of atoms or molecules in collisions against a particle - simulating the so-called Brownian motion. We believe that the use of this model will support the introduction of the concepts seen in the kinetic theory of gases in high school, as well as serve as complementary material to the use of the microscope in the observation of Brownian motion or even replace it in the case of its unavailability in school. For the application of this product in the classroom it is necessary to develop a didactic sequence containing initial questionnaire, texts, images, videos, experimental activities with the simulator, final questionnaire and students' opinion about the methodology adopted. Discussions about students' conceptual evolution on the constitution of the subject and the results of the evaluations are presented.