This work presents a didactic proposal to study atmospheric pressure. The introduction of technological resources in physics teaching is ever-increasing today. In this context, access to smartphones proves an accessible tool due to their massification and the possible uses of their built-in sensors. Therefore, we choose to use a smartphone as a barometer to measure the atmospheric pressure. We suggest experiments to measure atmospheric pressure as a function of height and time that can be easily reproduced by students in environments outside laboratories. The experimental results are compared with those provided by a meteorological station of the Company of Environmental Sanitation Technology of the State of São Paulo. Determining the atmospheric pressure variation as a function of height also allowed us to estimate the Boltzmann constant, thus establishing an experiment that can be introductory in statistical physics. Other than stimulating the practice and understanding of graphical analyses of experimental results, the proposed experiments serve as a deeper understanding of the atmospheric pressure phenomenon than that usually found in textbooks, proving to be a robust and suitable tool for physics teaching at an undergraduate level.

Modern electronic instrumentation techniques are being introduced in the programs of the Physics and Physical Engineering courses and, in this context, the programmable logic devices play an important role. We present the fundamental steps for the design, development, and validation of systems based on programmable logic devices. Two digital filters have been implemented for illustrating the guide procedures. The results show that the function–response complies with the common requirements of generic filter performance. This work is targeted at students and lectures and aims stimulate and challenge them to develop electronic instrumentation using programmable logic devices in teaching activities.

O estudo sobre a conservação do momento linear e as forças impulsivas nos cursos introdutórios de física tem abordagem baseada na colisão de objetos que se comportam como partículas. Neste trabalho busca-se por um aprofundamento no tema, introduzindo-se atividades experimentais direcionadas para laboratórios de ensino de física em que se considera a colisão entre uma bola de borracha e uma superfície rígida e plana. Estes experimentos permitem investigar características da colisão, tais como o tempo de impacto, a força impulsiva, a área de contato e o coeficiente de restituição. A modelagem, baseada na teoria de Hertz, inclui as propriedades elásticas da bola. Os resultados experimentais são comparados com valores teóricos provenientes do tratamento convencional (desconsiderando a deformação dos corpos) e da teoria de Hertz. Também são fornecidas indicações sobre a elaboração de experimentos visando aprimoramentos por parte de professores e alunos.

The study on the conservation of linear momentum and impulsive forces in introductory physics courses has an approach based on the collision of objects that behave as particles. In this work we search for a deepening in the subject, introducing experimental activities directed to laboratories of physics teaching in which it is considered the collision between a rubber ball and a rigid and flat surface. These experiments allow us to investigate collision characteristics, such as the impact time, the impulsive force, the contact area and the coefficient of restitution. The modeling, based on the Hertz's theory, includes the elastic properties of the ball. The experimental results are compared with theoretical values from the conventional treatment (excluding the deformation of the bodies) and the Hertz theory. Indications are also given about the elaboration of experiments aiming at improvements by teachers and students.

Os pêndulos são muito empregados nas atividades de ensino de cursos introdutórios de física. Nessas atividades, frequentemente, faz-se uso de modelos ideais para estudar o comportamento do pêndulo. Neste trabalho é sugerido um modelo que leva em conta o amortecimento das oscilações. Uma metodologia experimental é proposta com a finalidade de detectar a diminuição da amplitude das oscilações e ajustar estes dados a um modelo matemático. Os resultados demonstram que o pêndulo simples, composto de esferas de pequeno volume e oscilando com baixas velocidades, pode ser estudado por modelos simplificados. A metodologia e o modelo matemático são compatíveis com o nível de conhecimento de alunos de cursos introdutórios de física e oferecem uma visão mais realística sobre o comportamento do pêndulo.

The pendula are largely used in teaching activities of physical introductory courses. Often, in these activities an ideal model is used to study the behavior of the pendulum. In this work a model that takes into account the oscillation damping is suggested. An experimental methodology is purposed aiming to detect the falling down of oscillation amplitude and to fit these data to a mathematical model. The results show that the simple pendulum, set up by a small volume sphere and oscillating on low speed, can be studied with simplified models. The methodology and the mathematical model are appropriated for the knowledge level of the students from physic introductory courses and offer a more realistic insight about the pendulum behavior.