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Undergraduate Physics courses has one of the highest dropout rates in Brazilian universities. To face this problem, it is necessary a deep understanding of the causes that lead students to withdraw or persist in their undergraduate courses. Despite empirical research, the validation of a theoretical model that explains dropout and student persistence in the Brazilian context is a current challenge for researchers in the field. In this paper, we evaluate the suitability of the Tinto's Persistence Motivation Model, developed in the United States of America, to represent the scenario of an undergraduate Physics course at a Brazilian public university. We carried out a quantitative study from data collected with a questionnaire answered by 168 undergraduate students. The questionnaire brings up statements related to the predictors of student persistence according to the Tinto model (academic self-efficacy, sense of belonging and perception of curricular relevance) and the self-declared intention of persistence. Statistically significant correlations were identified between all constructs, endorsing the theory proposed by Tinto. The linear regression model was able to predict 37% of the variance of intention to persist. This indicates that the model partially represents the investigated setting. New studies must be done to identify other aspects that impact student persistence in the investigated context. [ABSTRACT FROM AUTHOR]

Hooke's law establishes a direct relationship between the applied force and deformation triggered on an object, with the elastic constant being the proportionality factor. Introductory Physics courses usually address Hooke's law in the context of real springs. This paper proposes a complementary didactic approach to the topic "elasticity of materials", considering a microscopic model in wich the interatomic bonding behave like springs. Thus, the elastic constant of these structures can be predicted by an extremely simple closed formula in the case of periodic systems. Particularly, monolayer hexagonal boron nitride structures were modeled from a series-parallel combination of identical springs. The model was developed within the linear approach of elasticity to ensure theoretical simplicity. A study was conducted to establish an optimal value corresponding to this regime, and 1.8% was determined as the maximum strain. The model was tested via atomistic computational simulations, being able to accurately predict the values of the elastic constants of the structures. Finally, the proposed approach proved to be didactically simple and interesting in introductory Physics or Engineering courses, mainly for the confirmation of the validity of the usual rules of spring combination in the microscopic domain. [ABSTRACT FROM AUTHOR]

In this paper, we approach different ways to use optical transformation matrices, or ABCD matrices, and optical simulations as tools for teaching geometrical optics. The work presented here ranges from simple situations, such as perfect flat lenses, to more complex situations, such as optical systems in media with different refractive indices. These examples can be easily solved with the use of optical matrices, a powerful tool, yet not widespread in undergraduate physics courses in the country. We will compare results from the classical equations for thin lenses and the matrix method with the results obtained through simulation with the freeware software OSLO EDU to show the power of the matrix method. With this proposal, the teacher will have new ways of approaching the problem and will facilitate both his didactics and student learning in the classroom or optical laboratories. Approaching geometrical optics in a different way will also enable real-world applications and the introduction of optical simulation software in the classroom. [ABSTRACT FROM AUTHOR]

In solving classical mechanics problems many times we are guided by a feeling of familiarity and analogies. Nevertheless, not always this a good strategy. This is the case of the problem of two masses in free fall in a uniform field which we discuss in this paper. [ABSTRACT FROM AUTHOR]

We describe a low-cost and playful apparatus for geometrical optics experiments that uses everyday materials. The experimental setup is simple and easy to manipulate, and it entails making spherical lenses with Jell-O. Using paper templates, created in the desired shape, we cut the Jell-O in the format of a spherical lens. Using these materials, we measured the refraction index of the lenses using Snell's Law and measured the focal distance of a convergent Jell-O lens. Using a Jell-O lens, we simulated how the crystalline lens in the human eye works. By stretching and compressing the Jell-O lens, it is possible to observe a change in the focal position, illustrating the mechanism of accommodation that occurs in the human eye. [ABSTRACT FROM AUTHOR]

Spring associations are often explored in Physics teaching through a theoretical model that defines the equivalent elastic constant of a set of springs in parallel as the sum of the spring constants of each of the associated springs. Like any scientific model, this representation is constructed by assuming a series of idealizations that delimit its validity domain. In the mentioned model, it is assumed that, when a force is applied, the associated springs extend equally, that is, they present a same deformation. For the case where two springs are used to sustain an object vertically, we will hardly have this condition respected In this paper, we present a discussion about the association of two springs in parallel from the perspective of the Bunge modeling process. We propose an expansion of the traditionally explored theoretical model considering the association of two parallel springs that do not deform equally. We also present an empirical comparison of the traditional model and the proposed expanded model. We understand that the discussion built has the potential to, besides providing the mobilization of basic physics knowledge, foster discussions about the representational role of scientific knowledge, enabling situations that demand reflection on the nature of Science. [ABSTRACT FROM AUTHOR]

This paper aims to show the essential aspects of the development of the physical concept of energy, in order to subsidize the choice of teachers about the best way to understand and teach this concept. We will study the thought of some of the main scientists who were interested on the subject, and the emerging debates around this topic. The paper is divided in two parts. Firstly, some contributions of Thomas Young, Johann Bernoulli, Galileo Galilei, René Descartes and Leibniz will be analyzed. Moreover, the evolution of the physical concept of energy in the context of machines and beyond the mechanics will be presented. The main idea that guides the discussion of this text is the fact that the development of the physical concept of energy is closely related to the development of the principle that there is a "constancy in the midst of change". That is, something is always constant despite changes in the environment. [ABSTRACT FROM AUTHOR]

This paper aims to show the essential aspects of the development of the physical concept of energy, in order to subsidize the choice of teachers on the best way to understand and teach this concept, and it is divided into two parts. Firstly, we have shown some contributions by Thomas Young, Johann Bernoulli, Galileo Galilei, René Descartes and Leibniz, and how was the evolution of the physical concept of energy in the context of machines and beyond the mechanics. In the second and final part, we have finished our analysis presenting some decisive contributions of Joule and Kelvin for the correct and modern formulation of the principle of conservation of energy and, consequently, of the physical concept of energy. Then, we have given our suggestion on how to approach this concept in the classroom. [ABSTRACT FROM AUTHOR]