Revista Mexicana de Física E

On Wien’s peaks

Ernesto Marin, Antonio Calderón — Fri, 05 Jan 2024 00:00:00 +0000

Most Modern Physics Books contain a chapter on the Laws of Black Body radiation when introducing the principles of Quantum Mechanics. These laws govern many phenomena that we encounter in daily life, technological developments, and scientific research. For that, this old subject is still of great importance, and even now some issues require our attention. This work addresses one of these topics. We describe why it has no sense to think that the wavelength at which Planck’s black-body spectral radiance distribution plotted as a function of the wavelength has its maximum value, must be the same that the wavelength calculated from the peak value obtained when the distribution is plotted as a function of another variable, such as the energy of the photons. We will show how the issue lies in using the correct form to calculate this wavelength from measured quantities.

Lagrangian analysis of the Feynman paradox

Gerardo Francisco Torres del Castillo — Fri, 05 Jan 2024 00:00:00 +0000

It is shown that the direct use of the Lagrange equations allows us to analyze the entire process involved in the Feynman paradox, without having to speak of the angular momentum of the electromagnetic field.

Two ways to slower aging - or just one?

Friedrich Herrmann, Michael Pohlig — Fri, 05 Jan 2024 00:00:00 +0000

In the context of teaching relativity, one encounters two situations in which two observers age at different rates. Usually, these effects are treated as if they were independent of each other. Often one is referred to as special-relativistic, the other as general-relativistic. We show that both are special cases of an effect which follows naturally from the fact that space and time form a unity. They exist in a flat space-time and therefore neither of them deserves the label general relativistic.

GUI for conic sections: parabola, ellipse and hyperbola

Saima Gul, Muhammad Yousuf Tufail — Fri, 05 Jan 2024 00:00:00 +0000

In this paper we provide three Excel spreadsheets for the explanation of Parabola, Ellipse and Hyperbola respectively. Our target audience is University science students (Physics/Mathematics/Computer science) and mentors.

Demonstrating optical-path compensation in a Michelson interferometer

Neil Bruce, Iván Montes-González — Fri, 05 Jan 2024 00:00:00 +0000

In this paper we present a simple experiment using a fully compensated Michelson interferometer and a white-light source to demonstrate the importance and the effects of the optical-path compensation. Polyester sheets are introduced in one of the arms of the interferometer to partially decompensate the system. The change in mirror position required to see the fringes in these two cases is related to the refractive index and the thickness of the polyester sheets, and the degradation in the contrast of the white-light fringes due to the partial compensation can easily be demonstrated.

The isothermal process peculiarities in the presence of gas leak from a vessel

Vladimir Valerievich Ivchenko — Fri, 05 Jan 2024 00:00:00 +0000

We construct the simple mathematical model which uses only the equation of state of an ideal gas and allows one to find the relationship between the gas pressure and volume in the case of gas leak during its isothermal compression. Among other results, there may be a saturation effect of the pressure, when it remains constant under compression. We present a simple physical explanation of this effect.

The motion of a particle on the surface of a general cone

Diego Gerardo Gómez Pérez, Omar Gonzalez Amezcua — Fri, 05 Jan 2024 00:00:00 +0000

We use the formalism of Lagrange to find the equations of motion of a particle on the inner surface of a “general cone”. The equations of motion are challenging to solve, but we can evaluate them numerically with different software, to obtain the particle’s trajectory on the surface as a function of parameters such as angular momentum L_θ, cone shape and initial conditions, and then we find the total free-fall time of the particle. The results show a special cone in which the free fall time has a minimum for a fixed angular momentum and fall height. Differences in the free-fall times and the particle’s trajectory also analyzed for a two-coordinate (r, z) and three-coordinate (r, θ, z) system. This work shows the importance of learning to use software (Wolfram Mathematica, Python, POV-Ray) to help with some complex theoretical problems. Finally, the results can easily be generalized for other more complex surfaces.

Measuring the refraction index of luminescent carbon nanodots forming Gaussian beam using the tracker software

Fri, 05 Jan 2024 00:00:00 +0000

Nanotechnology is currently regarded as one of the fastest-growing technologies. Equipping students with some understanding of nanotechnology in relation to physics ideas may trigger their interest and inspire them to learn physics. This study is aimed to measure the refraction index of Cdots solution using the Gaussian beam and Tracker software. The method used in this research is quantitative descriptive method with the stages of research that include designing, construction, developing, and testing the measuring instrument. The procedure in this study begins by preparing the Cdots solution from cajuput oil (CJO) distillation wastes. The Cdots are then characterized using the UV-visible (UV-Vis), photoluminescence (PL), time resolved-PL (TRPL), and Fourier transform infrared (FTIR) spectroscopies. The Cdots solution is then put into a reaction tube with solution height variation. The violet/UV laser pointer is exposed upward towards the Cdots solution from the bottom of the reaction tube producing a Gaussian beam inside the reaction tube. The Gaussian beam is then photographed, which then the format is converted into a video format. The video format of the Gaussian beam is analyzed using the Tracker software. The characterizations of the Cdots show i) an absorption peak at a wavelength of 216.0 nm, ii) an emission peak at 512.29 nm indicating cyan luminescence, iii) an electronic lifetime of 51.3 ns, and iii) functional groups of O-H; C=C; and C=O. Moreover, the Gaussian beams are formed for various heights of the Cdots solution, i.e.: from 5.364 cm to 13.000 cm. Using the Tracker software, the value of the Cdots’ refraction index is 1.29 0.03, which is comparable to the refraction index of water. This measuring instrument has the potential to be used in high school physics classes and/or first-year university physics courses.

La energía es un ente que hace posible la transformación

José Manuel Alvarado Reyes — Fri, 05 Jan 2024 00:00:00 +0000

Energy. What mysteries does it hide? both for those engaged and for those disinterested in science. The committed use and calculate energy with certainty, and the disinterested only know of its existence. However, both understand and share the same idea: energy is everything, it is life and the universe itself. For those who are indifferent to science, it is enough to understand that it is very important in their daily life, for science students themselves it is enough to know that their existence is of great importance in everything that occupies a volume in space. In today's advanced science courses, energy is a dogma for students and a riddle for educators; however, it is a phenomenon used with great certainty of its existence and with small uncertainties in its evaluation. However, to this day it is known that it is something abstract and it is difficult, or impossible to define, understand or simply explain what energy is, but we know that it is real, it exists and governs everything that surrounds us. In the present work a concept of energy is proposed from the philosophical point of view, supported more as a real entity and nothing imaginary.

Energía. ¿Qué misterios esconde? tanto para los comprometidos como para los desinteresados en la ciencia. Los comprometidos, utilizan y calculan la energía con certeza, y los desinteresados sólo saben de su existencia. Sin embargo, ambos entienden y comparten la misma idea: la energía lo es todo, es la vida y el universo mismo. Para los que indiferentes en la ciencia, basta con entender que es muy importante en su vida diaria, para los propios estudiantes de ciencias basta con saber que su existencia es de gran importancia en todo lo que ocupa un volumen en el espacio. En los cursos de ciencia avanzada de hoy, la energía es un dogma para los estudiantes y un enigma para los educadores; sin embargo, es un fenómeno utilizado con gran certeza de su existencia y con pequeñas incertidumbres en su evaluación. Sin embargo hasta el día se sabe que es algo abstracto y es dificil, o imposible de definir, entender o simplemente explicar qué es la energía, pero sabemos que es real, existe y gobierna todo lo que nos rodea. En el presente trabajo se propone un concepto de energía desde el punto de vista filosófico, sustentado más como un ente real y nada imaginario.

On the quantum problem with harmonic, Stark, Coulombian and centrifugal barrier potential terms, and biconfluent Heun functions

D. M. Reyna-Muñoz, Marco A. Reyes, A. Fernández-Téllez — Fri, 05 Jan 2024 00:00:00 +0000

We show here that the one dimensional Schro ̈dinger problem with a potential function with harmonic, Stark, Coulombian and centrifugal barrier terms can be described in terms of biconfluent Heun functions, and review some possible solutions of the problem. Considering the algebraic form of the quantum problem, we readily find two new relations between biconfluent Heun functions, which have not been considered before in the literature.

On the dynamics of a rolling spherical charged shell

Aldrin Cervantes Contreras, Abel Santillán Rodríguez, Luis Gerardo Soria Silva — Fri, 05 Jan 2024 00:00:00 +0000

In this work, we investigate the behaviour of a charged spherical shell rolling on an inclined plane, in presence of a point charge located at the lowest part of the inclined plane. The shell generates two magnetic fields, one due to its rotation and another due to its translation, These magnetic fields affect the shell through self-inductance. On the other hand, the charge in the lowest part of the inclined plane interacts with the shell, and we find that under certain conditions the spherical shell rolls back and up the inclined plane due to the electric force. We perform a numerical analysis to study this behavior.

A catenary-like cable confined in a circular cylinder

E. G. M. de Lacerda, Hector Carrion Salazar — Fri, 05 Jan 2024 00:00:00 +0000

The problem of obtaining the curve of a cable suspended between two points, supporting only its own weight, was solved simultaneously, in the 17th century, by Johann Bernoulli, Leibniz, and Huygens. This curve is called the catenary. This article solves a modified problem in which the suspended cable is confined in a vertical cylinder. For this, an functional is formulated to describe the potential energy of a fixed-length confined cable in any possible arrangement. Then, the variational problem of extremizing this functional is presented and the Euler-Lagrange differential equation is deduced. The analytical solution of this equation is obtained for the cable suspended by two points at equal and different heights. Furthermore, the tensile force acting on the cable is determined. Numerical results are presented comparing the effect of confinement on the tensile force in relation to the traditional catenary.

Research skills R+D+I and industry 4.0, STEM and TRIZ and their application in the professional skills of applied physics students

Silvia Magdalena Coello Pisco, B. Rodríguez, L. Banguera, E. Baidal — Fri, 05 Jan 2024 00:00:00 +0000

The advancement of science and technology requires that future professionals in all fields of study have developed certain professional and investigative skills. The impact of the industrial revolution 4.0 has included the education sector. For these reasons, we designed a chart based on five competencies that are essential for the professional improvement of future graduates of the Engineering career. These competencies were: industry 4.0, TRIZ, STEM and research competencies in R+D+i projects. A didactic material was prepared to be applied to 225 basic level students in the subject of Applied Physics together with a rubric that determines the skills that the participants have developed during their study from the upper secondary level to the basic level of the career. engineering. The quantitative analysis of the study was carried out with inferential descriptive statistics, in which we found that the students have not developed certain skills: social skills, leadership, cooperative work, assertive communication, demotivation, lack of interest in contributing ideas in group work, no they know how to assign roles. A qualitative technique of motivational didactic development (survey of previous motivations, prejudices and feelings) and the inventive TRIZ were applied to promote the development of certain skills in students. The qualitative analysis of the study was carried out with the Chi Square technique, the results of our research confirm that the didactic-pedagogical-experimental technique has a significant impact on the improvement or development of professional skills in students regardless of the skills acquired in previous years. levels

Development of natural sciences e-modules based on android with a science, environment, technology, and society approach in the earth structure chapter

Tutik Yuliatun; Himawan Putranta, Kristina Uskenat — Fri, 19 Jan 2024 00:00:00 +0000

The matter of the structure of the earth and its dynamics require sufficient visualization to imagine how the structure, layers of the earth, and things that can happen, such as earthquakes. Teachers have not used supportive media when delivering material on the structure of the earth and its dynamics, so students tend to have difficulty understanding the material. This study aims to produce a natural science e-module-based android with a science, environment, technology, and society (SETS) approach that is suitable for learning material on the structure of the earth and its dynamics. This research method uses a research and development (R&D) 4D model with four stages, namely defining, designing, developing, and distributing. The subjects of this study were 9 students of class VIII Islamic junior high school in Yogyakarta in the 2020/2021 academic year. The instruments used in this study were interview sheets and questionnaire sheets. Interview sheets are used to obtain information about data on media needs/learning resources needed by schools. While the validation sheet is used to determine the feasibility of the developed e-module. From the results of the validation analysis of material experts and media experts, the average score was 3.79 and 3.685, respectively. Meanwhile, from the results of the limited product trial, an average score of 3.84 was obtained. From the data analysis, it was concluded that the development of a natural science e-module-based android with the SETS approach on the material of the earth's structure and dynamics was suitable for use in learning. This E-Module can be used anywhere and trains students' independence in learning.

The free fall in three Physics theories

Fri, 19 Jan 2024 00:00:00 +0000

This paper explores the interplay between Classical Mechanics, Relativistic Mechanics, and Quantum Mechanics through an analysis of the free fall phenomenon. We investigate the probability density functions and corresponding plots in each theory, alongside calculating the expected values of position and momentum. By observing the behavior of these results as they approach the classical limit, we confirm the hypothesis that these theories can be connected through their probability density functions. Furthermore, we discuss the validity of the correspondence principle in Quantum Mechanics, while also examining, in a non-rigorous manner, the validity of the weak equivalence principle within each of the aforementioned theories.

A simple filter Lorenz electronic circuit

Isaac Campos-Cantón — Fri, 26 Jan 2024 00:00:00 +0000

In this work, an electronic circuit of the Lorenz system is developed. The electronic circuit proposed is one of the easiest to implement. We changed the x-state equation of Lorenz‘s system with a low-pass filter to an RC circuit with the same cutoff frequency. Corron‘s electronic circuit is used as the basis for electronic design. Simulation results support this proposal.