Vol. 61 No. 1 Jan-Jun (2015): Revista Mexicana de Física E
Published:
2015-01-01
Artículos
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Diseño de práctica de laboratorio para uso de la creatividad: Canal de olas
Abstract:This paper describes the experiences of teachers teaching Physics II Laboratory, at the School of Marine Sciences of the UABC, in which the student modifies a device in order to measure the water level in a wave tank. The students are only allowed to use a computer mouse as a sensor. The students have access to a piece of MATLAB code that reads the number of pixels that the mouse has been moved. Using that code and their creativity, the students must modify the mouse to obtain a device that directly measures the movement of the water surface and, in doing so, registers the characteristics of the water waves in the tank. It is important to note that the oceanography program does not include courses in electronics, so students cannot build a data acquisition card. This experiment covers various educational factors allowing students to adapt a device in order to construct their own gauge to directly measure a phenomenon and to record digitally, encouraging the reuse of technology for profit and the innovation of alternative uses for the mouse in the measurement of physical variables.⬇️ Scroll down to see the full summary -
Obtención y solución a la ecuación de movimiento de un cohete, actuando sobre él las fuerzas externas del campo gravitacional constante y el rozamiento del aire proporcional a la velocidad
Abstract:In this work will be studied the variable mass system for the particular case of rocket problem, with intend obtain the equation that govern its movement and solve after under homogeneous gravitational field conditions and air resistance, know to allow the physics quantities, like velocity and position in all time. Furthermore get the rocket solution for the case that only acts the gravitational force on it, that allows to observe the difference between both solution. The found solution in this paper for this problem doesn't appear in the literature, such that this work purport dazzle the enigmatic solution of rocket problem. \begin{comment} In this work we studied the variable mass system for the particular case of rocket problem. With intend to obtain the equation that governs its movement and to solve under homogeneous gravitational field conditions and air resistance, that allow to know the velocity and position at all times. Furthermore we get the rocket solution for the case in which only acts the gravitational force, that allows to observe the difference between both solutions. The solutions found in this paper for this problem do not appear in the literature. This work pretends shed some light on the enigmatic solution of rocket problem. \end{comment}⬇️ Scroll down to see the full summary -
Obteniendo los coeficientes de restitución y arrastre en un solo experimento
Abstract:In this paper is shown a simple and novel way of finding the coefficient of restitution for the collision between a ball and the floor, where also the drag coefficient of a spherical shape is obtained.⬇️ Scroll down to see the full summary -
Validating quantum storage and state transference based on spin systems through elimination of exchange degeneracy
Abstract:A quantum storage and state transference machine based on spin systems is considered. The process described cannot be regarded a a quantum teleportation because it does not involve any measurement. In previous work on quantum storage and state transference based on spin systems, exchange degeneracy was not taken into account and this is important because the initial and final states can become indistinguishable from each other and so the state transference may loose its meaning. It is shown that such a failure can be corrected by symmetrization. We conclude that in a consistent state transference and storage process, the parity of the initial state is not necessarily conserved.⬇️ Scroll down to see the full summary -
Packing of monosized spheres in a cylindrical container: models and approaches
Abstract:Packing of monosized spheres in a cylindrical container of a fixed diameter is a frequently discussed subject in recent studies. It is motivated by the high applicability of these models, particularly by the advances in nanomaterial science and engineering, associated with the development of hierarchically ordered matters of specific structures and properties. Their features strongly depend on the arrangement and density of the filling atoms in the channels of a nanostructured porous matrix. A special interest is devoted to a dense random packing, which by its nature is not totally random when the spheres do not overlap. In this paper, related models of packing are classified basing on the space filling method, and the densities reached theoretically as well as experimentally for those classes are given. The effects produced by some parameters on the packing density and the main properties are analyzed. The experimental techniques and computer modeling approaches are summarized.⬇️ Scroll down to see the full summary -
Understanding the arithmetic of color
Abstract:In this work we propose to introduce Arithmetic for the Mixture of Colors, which can be defined from dividing the electromagnetic spectrum of white light in three thirds, and by associating each of them to an algebraic expression of the three primary additive and subtractive colors. Then, we will give the rules for adding or subtracting to predict the new mixture of resultant colors.⬇️ Scroll down to see the full summary -
Velocidad de evaporación del agua
Abstract:Among the phenomena or transformations that happen in the natural water cycle, undoubtedly one of them is evaporation. In order to get conscience of its importance, and to be able to contribute in the human activities to ensure the availability of freshwater, it is necessary to quantify the phenomenon when it happens at room temperature. In this paper a simple experiment is presented in which the speed of evaporation is determined. The experiment is proper to perform, in the general physics laboratory, by students of the first year in careers of basic sciences or engineering.⬇️ Scroll down to see the full summary -
Modelando un punto cuántico: una aproximación pedagógica
Abstract:We determine the energy performance of an electron inside a quantum dot. The quantum dot is modeled using a infinite potential well and a two-dimensional harmonic oscillator and solved through the formalism of second quantization. This system has a high relevance for their potential applications in the construction of devices for quantum information processing. This description presents the applications of classical problems of quantum mechanics in the design and construction of opto-electronics devices and can be used in applied physics courses at undergraduate or postgraduate level.⬇️ Scroll down to see the full summary -
Euler y los absolutos
Abstract:This work seeks to discuss the arguments posed by Leonhard Euler (1707-1783) in favour of considering space, time and movement as absolute concepts as opposed to relational ones. To this end, points made by Euler concerning this topic are analyzed in four of his works: Mechanica Sive Motus Scientia Analytice (1737), Reflexions sur l'espace et le temps (1748), Lettres a una princesse d'Allemagne sur divers sujets de physique \& de philosophie (written between 1760 and 1762), and Theoria Motus Corporum Solidorum Seu Rigidorum (1765).⬇️ Scroll down to see the full summary -
Simetría y Degeneración: partícula atrapada en una caja cúbica con paredes impenetrables
Abstract:In physics as well as in chemistry the importance of symmetry is widely acknowledged. It is of common knowledge that the systems' degeneracy, in the domain of linear physical systems, is tightly related with symmetry. The stationary state degeneracy should correspond with the dimension of the symmetry group irreducible representations (irreps) associated. Therefore identifying the symmetry group is essential for labeling the energy levels. Sometimes the spectrum presents systematic accidental degeneracy, which means that the supposed symmetry group is actually a subgroup. This is the case for a particle in a cubic box, with impenetrable walls. This article presents the procedure that allows the identification of the new symmetry group that explains the degeneracy. Furthermore examples to illustrate the concepts are presented as well as the consequences implied in the selection rules.⬇️ Scroll down to see the full summary
