El smartphone como barómetro en experimentos de Física

Abstract

En este trabajo se presentan dos experimentos que sacan partido del sensor de presión de los teléfonos inteligentes, utilizándolo para determinar su valor en el seno de agua en equilibrio en una probeta. En un primer experimento, destinado a estudiantes de Secundaria y niveles superiores, las medidas de la presión obtenidos a diferentes profundidades permiten realizar un ajuste lineal, comprobando así la validez de la Ley de Stevin. Además, a partir de dicha ley y de los parámetros del ajuste se puede determinar la densidad del agua. Los valores obtenidos indirectamente por este procedimiento difieren entre un 2 % y un 4 % del resultado de dividir entre sí la masa y el volumen de una muestra. En un segundo experimento, más enfocado a estudiantes de primeros cursos universitarios de asignaturas de Física, el teléfono móvil sumergido oscila suspendido de un muelle. Las medidas del sensor de presión permiten, mediante la Ley de Stevin, obtener la serie temporal de la presión en la correspondiente oscilación amortiguada, cuyos parámetros se determinan mediante un ajuste no lineal. La comparación de la pulsación libre obtenida a partir de estos valores difiere en un 1, 5 % respecto del obtenido a partir de la medición directa del periodo fuera del agua. En ambos casos, los resultados obtenidos indican la efectividad del método utilizado en contextos docentes. This paper presents two experiments that take advantage of smartphones pressure sensor, using it to determine the value of the pressure within in equilibrium water in a test tube. In a first experiment, aimed at students of secondary and higher levels, the data collected with the pressure sensor of a smartphone at different depths allow a linear fit, thus checking the validity of Stevin's Law. In addition, based on this law and the parameters of the adjustment it has been possible to determine the density of the water. The density values obtained indirectly by this procedure differ between 2 % and 4 % of the result of dividing the mass and volume of a sample. In a second experiment, more focused on students of the first university courses of Physics subjects, the submerged smartphone oscillates suspended from a spring. The measurements of the pressure sensor allow, through Stevin's Law, to obtain the time series of the pressure in the corresponding damped oscillation, whose parameters are determined by a non-linear adjustment. The comparison of the free pulsation obtained from these values differs by 1.5 % from that obtained from the direct measurement of the period outside the water. In both cases, the results obtained indicate the suitability of the current methodology in teaching contexts.Palabras clave: teléfonos inteligentes, hidrostática, enseñanza de la Física.

Un laboratorio de ciencias en tu bolsillo

“…A través del sensor de presión podemos utilizar el smartphone como barómetro. Al introducirlo protegido en un líquido, y midiendo la presión en función de la profundidad, se pude determinar fácilmente la densidad del líquido (Salinas, 2018b). Entre las propuestas más llamativas de SMARTPHYSICS se puede destacar el estudio de la eficiencia luminosa de una lámpara con el sensor de luz ambiente de un smartphone (Sans, 2017), el estudio de movimientos mediante las variaciones de intensidad (Sans, 2013), y la caracterización de fuentes luminosas lineales (Salinas, 2018c) que se muestra en la Fig.…”

Smartphone and teamwork as a methodological tool for teaching and learning physics

“…It is worth emphasizing the manifesto of several authors with respect to the favorability of students in childhood with respect to science, which decreases with advancing age; this is evidenced in secondary school in the upper grades with not very encouraging results in technical scientific studies, particularly in chemistry, mathematics, and physics [4][5][6][7][8]. There are several causes for the lack of interest of students in this field; some are focused on the lack of innovation in strategies that reflect the importance and dynamics of sciences well used in favor of society, and that teachers encourage them to solve problems that arise in the environment [1,2,9].…”

“…[11,12]. Based on some difficulties related to kinematics, the following are described: Considering force as the cause of movement, considering that the bigger and heavier an object is and the more it weighs the faster it will fall, not having clear signs of acceleration, confusing the concept of acceleration with that of velocity, among others [4].…”

Analyzing Atmospheric Pressure Variations in Time and Height: a Didactic Proposal Employing a Smartphone Barometer

“…Using atmospheric pressure and temperature sensors on an Arduino platform, Carvalho and Amorim [33] reported the tidal behavior of barometric pressure throughout the day. Taking advantage of a built-in smartphone barometer sensor, Salinas et al [39] propose two valuable experiments to explore vertical changes of pressure in water, allowing for the determination of the density of salty water and the study of pressure oscillations due to mechanical damped oscillations.…”