Martín Monteiro

Mostramos como los sensores incorporados en dispositivos móviles pueden ser utilizados como laboratorios portátiles al servicio de la enseñanza de las ciencias experimentales, especialmente de la física, en los últimos años de la educación media y los primeros de la universitaria. Describimos experimentos que antes requerían costosos aparatos o que no eran factibles en laboratorios de enseñanza. Finalmente, discutimos algunas perspectivas del uso de los sensores en la enseñanza de la física.

We propose a home laboratory in which a telescopic vacuum cleaner pipe and a smartphone are used to investigate sound speed and acoustic resonance. When the pipe is hit or the hands clapped near one end, the sound produced is registered by a smartphone. The resonant frequency is obtained using a smartphone and an appropriate application. Varying the pipe’s length and registering the corresponding resonant frequency allows to obtain the sound speed. This home-lab, first proposed during Covid-19 pandemic, has been incorporated as a home challenge to experiment with acoustic resonance in new normal times.

This Resource Letter provides a guide to the literature on teaching experimental physics using sensors in tablets, smartphones, and some specialized devices. After a general discussion of hardware (sensors) and software (apps), we present resources for experiments using mobile-device sensors in many areas of physics education: mechanics, oscillations and waves, optics, electromagnetism, matter, modern physics, and astronomy.

A physical pendulum with variable point of suspension (and, as an outcome, variable inertia moment) is experimentally analysed. In particular, the period of the small oscillations as a function of position of the suspension point is measured using three different methods: a smartphone used both as an independent tool or as a data-logger and commercial photo-gate. The experimental results are successfully compared with theoretical calculations based on the addition of inertia moments and the Steiner theorem.

In this paper we discuss the use of sensors incorporated in mobile devices as possible mobile laboratories at the service of teaching experimental sciences. Mobile devices, smartphones, tablets, laptops, microbit cards, are a resource for making measurements of the physical world, since they have a set of built-in sensors that allow to measure position, linear speed, angular speed, acceleration, pressure, sound, color, magnetic field, proximity or luminosity, among others. Also, these devices have greatly improved the performance of their video cameras, allowing to easily shoot at high speed and high resolution. Given its portability it is possible to work in the laboratory itself or in other areas such as a gym, a park or your own home, transcending the traditional scope of the laboratory. In general, the measurements obtained can be analyzed in the device itself or uploaded to the cloud to be analyzed la

In the last years, numerous Physics experiments using smartphone sensors have been reported in the literature. In this presentation we focus on a less-explored feature of the smartphones: the possibility of using (measure and register data) simultaneously with more than one sensor. To illustrate, in the field of mechanics simultaneous use of the accelerometer and gyroscope (angular velocity sensor) or in optics experiments synchronous use of the ambient light and orientation sensors have been proposed. Indeed, this is a characteristic that simplifies experimental setups allowing to see through the physics concepts and, last but not least, reducing the costs.

We propose a set of modern and stimulating activities related to the teaching of Astronomy orientated to high school or university students using smartphones. The activities are: a) the experimental simulation of asteroid light curves including the determination of the period of rotation of asteroids, b) the experimental simulation of exoplanet detection by transit method, c) the experimental simulation of stellar distances using parallax and d) the use of virtual and augmented reality.

Originally an empirical law, nowadays Malus' law is seen as a key experiment to demonstrate the transverse nature of electromagnetic waves, as well as the intrinsic connection between optics and electromagnetism. In this work, a simple and inexpensive setup is proposed to quantitatively verify the nature of polarized light. A flat computer screen serves as a source of linear polarized light and a smartphone (possessing ambient light and orientation sensors) is used, thanks to its built-in sensors, to experiment with polarized light and verify the Malus' law.

The characteristics of the inner layer of the atmosphere, the troposphere, are determinant for the earth's life. In this experience we explore the first hundreds of meters using a smartphone mounted on a quadcopter. Both the altitude and the pressure are obtained using the smartphone's sensors. We complement these measures with data collected from the flight information system of an aircraft. The experimental results are compared with the International Standard Atmosphere and other simple approximations: isothermal and constant density atmospheres.

Nuestro mundo está cada vez más influenciado por la ciencia y la tecnología. En consecuencia, la comprensión pública de la ciencia es un factor clave en el desarrollo social, económico y sostenible. Aunque la divulgación científica ha crecido significativamente, la mayoría de las actividades se realizan en inglés. Por lo tanto, la creación y disponibilidad de contenido educativo y científico en español latino ha sido descuidada y obstaculizada. Como resultado, los latinoamericanos tienen poco acceso a contenido adecuado, confiable y culturalmente relevante sobre comunicación científica. Para abordar este tema, un grupo de científicos de diversas disciplinas y países se reunieron para crear la Red Latinoamericana de Cultura Científica (RedLCC). La RedLCC es una iniciativa regional de base que une fuerzas para la difusión de contenidos sobre ciencia y tecnología en español. Desde sus diferentes disciplinas y antecedentes culturales, los miembros de esta red multinacional están comprom...

The dynamics of a traditional toy, the yoyo, is investigated theoretically and experimentally using smartphone' sensors. In particular, using the gyroscope the angular velocity is measured. The experimental results are complemented thanks to a digital video analysis. The concordance between theoretical and experimental results is discussed. As the yoyo is a ubiquitous, simple and traditional toy this simple proposal could encourage students to experiment with everyday objects and modern technologies.

The shape of liquid surface in a rotating frame depends on the angular velocity. In this experiment, a fluid in a rectangular container with a small width is placed on a rotating table. A smartphone fixed to the rotating frame simultaneously records the fluid surface with the camera and also, thanks to the built-in gyroscope, the angular velocity. When the table starts rotating the surface evolves and develops a parabolic shape. Using video analysis we obtain the surface's shape: concavity of the parabole and height of the vertex. Experimental results are compared with theoretical predictions. This problem contributes to improve the understanding of relevant concepts in fluid dynamics.

The flight of a quadcopter drone, readily available as a toy, is analyzed using simple physics concepts. A smartphone with built-in accelerometer and gyroscope was attached to the drone to register the accelerations and angular velocities along the three spatial axis while the drone is taking off, landing or rotating. The vertical speed, the height and one of the angular coordinates are obtained through numerical integration of the acceleration values and compared with information provided by the manufacturer. The analysis of these quantities provides an opportunity to gain insight into important physics concepts involving Newton laws and conservation principles in a stimulating environment.

La ecuación de Bernoulli, que bajo ciertas condiciones relaciona la presión de un fluido ideal en movimiento con su velocidad y su altura, es un tema central en los cursos de F́ısica General para estudiantes de Ciencias e Ingenieŕıa. Frecuentemente, en los libros de texto utilizados en cursos universitarios, al igual que en diversos medios de divulgación, se suele extrapolar este principio para explicar situaciones en las que no es válido. Un ejemplo habitual es suponer que, en cualquier situación, mayor velocidad implica menor presión, conclusión correcta solo en algunas circunstancias. En este trabajo presentamos los resultados de una investigación con estudiantes universitarios, sobre las concepciones alternativas presentes en dinámica de fluidos. Encontramos que muchos estudiantes, incluso después de haber transitado por los cursos de F́ısica General, no han elaborado un modelo adecuado acerca de la interacción de un elemento de un fluido con su entorno y extrapolan la idea que ...

INTRODUCTION: Engineering students must deal with the errors, statistical or systemati, inherent to all physical measurements and be conscious of the necessity to express their as a best estimate and a range of uncertainty. OBJECTIVE: present a modern state-of-the-art approach to teach error analysis and uncertainties in the first years of engineering studies avoiding manual repetitive observations. METHODS: The main aspects addressed are the physical meaning of the mean value and standard deviation, and the interpretation of histograms and distributions. Other activities focus on the intensity of the fluctuations in different situations, such as placing the device on a table or held in the hand in different ways and the number of measurements in an interval centered on the mean value as a function of the width expressed in terms of the standard deviation. As applications to every day situations we discuss the smoothness of a road or the different positions to take photographs both ...

Experimental analysis of the motion in a system of two coupled oscillators with arbitrary initial conditions was performed and the normal coordinates were obtained directly. The system consisted of two gliders moving on an air track, joined together by a spring and joined by two other springs to the fixed ends. From the positions of the center of mass and the relative distance, acquired by analysis of the digital video of the experiment, normal coordinates were obtained, and by a non linear fit the normal frequencies were also obtained. It is shown that although the mass of the springs is relatively small compared to that of the gliders, when it is taken into consideration agreement with the experimental results is appreciably improved.

Smartphone usage has expanded dramatically in recent years worldwide. This revolution also has impact in undergraduate laboratories where different experiences are facilitated by the use of the sensors usually included in these devices. Recently, in several articles published in the literature,1,2 the use of smartphones has been proposed for several physics experiments. Although most previous articles focused on mechanical experiments, an aspect that has received less attention is the use of rotation sensors or gyroscopes. Indeed, the use of these sensors paves the way for new experiments enabling the measurement of angular velocities. In a very recent paper the conservation of the angular momentum is considered using rotation sensors.3 In this paper we present an analysis of the rotational energy of a physical pendulum.

Recently, two technologies: video analysis and mobile device sensors have considerable impacted Physics teaching. However, in general, these techniques are usually used independently. Here, we focus on a less-explored feature: the possibility of using supplementary video analysis and smartphone (or other mobile devices) sensors. First, we review some experiments reported in the literature using both tools. Next, we present an experiment specially suited to compare both resources and discuss in detail some typical results. We found that, as a rule, video analysis provides distances or angular variables, while sensors supplies velocity or acceleration (either linear or angular). The numerical differentiation of higher derivatives, i.e. acceleration, usually implies noisier results while the opposite process (the numerical integration of a temporal evolution) gives rise to the accumulation of errors. In a classroom situation, the comparison between these two techniques offers an opport...

The estimation of the electric field in simple situations provides an opportunity to develop intuition about the models used in physics. We propose an activity aimed at university students where the electric field of a finite line of charge is compared, analytically or numerically, with the fields of an infinite line and of a point charge. Contrary to intuition, it is not necessary to get very close for the line charge to be considered infinite, nor to move very far away for the finite line field to resemble that of a point charge. We conducted this activity with a group of students and found that many of them have not yet developed an adequate intuition about the approximations used in electromagnetism. Video Abstract: How far away is infinity? An electromagnetics exercise to develop intuition regarding models

Science students must deal with the errors inherent to all physical measurements and be conscious of the need to expressvthem as a best estimate and a range of uncertainty. Errors are routinely classified as statistical or systematic. Although statistical errors are usually dealt with in the first years of science studies, the typical approaches are based on manually performing repetitive observations. Our work proposes a set of laboratory experiments to teach error and uncertainties based on data recorded with the sensors available in many mobile devices. The main aspects addressed are the physical meaning of the mean value and standard deviation, and the interpretation of histograms and distributions. The normality of the fluctuations is analyzed qualitatively comparing histograms with normal curves and quantitatively comparing the number of observations in intervals to the number expected according to a normal distribution and also performing a Chi-squared test. We show that the ...

Remotely-controlled helicopters and planes have been used as toys for decades. However, only recently, advances in sensor technologies have made possible to easily flight and control theses devices at an affordable price. Along with their increasing availability the educational opportunities are also proliferating. Here, a simple experiment in which a smartphone is mounted on a quadcopter is proposed to investigate the basics of a flight. Thanks to the smartphone's built-in accelerometer and gyroscope, take off, landing and yaw are analyzed.

La ecuación de Bernoulli, que bajo ciertas condiciones relaciona la presión de un fluido ideal en movimiento con su velocidad y su altura, es un tema central en los cursos de Física General para estudiantes de Ciencias e Ingeniería. Frecuentemente, en los libros de texto utilizados en cursos universitarios, al igual que en diversos medios de divulgación, se suele extrapolar este principio para explicar situaciones en las que no es válido. Un ejemplo habitual es suponer que, en cualquier situación, mayor velocidad implica menor presión, conclusión correcta solo en algunas circunstancias. En este trabajo, reportamos los resultados de una investigación con estudiantes universitarios, sobre las concepciones alternativas presentes en dinámica de fluidos. Encontramos que muchos estudiantes, incluso después de haber transitado por los cursos de Física General, no han elaborado un modelo adecuado acerca de la interacción de un elemento de un fluido con su entorno y extrapolan la idea que ma...

Science students must deal with the errors inherent to all physical measurements and be conscious of the necessity to express their as a best estimate and a range of uncertainty. Errors are routinely classified as statistical or systematic. Although statistical errors are usually dealt with in the first years of science studies, the typical approaches are based on performing manually repetitive observations. Here, based on data recorded with the sensors present in many mobile devices a set of laboratory experiments to teach error and uncertainties is proposed. The main aspects addressed are the physical meaning of the mean value and standard deviation, and the interpretation of histograms and distributions. Other activities focus on the intensity of the fluctuations in different situations, such as placing the device on a table or held in the hand in different ways and the number of measurements in an interval centered on the mean value as a function of the width expressed in terms ...

We propose a simple experiment to explore magnetic fields created by electric railways and compare them with a simple model and parameters estimated using easily available information. A pedestrian walking on an overpass above train tracks registers the components of the magnetic field with the built-in magnetometer of a smartphone. The experimental results are successfully compared with a model of the magnetic field of the transmission lines and the local Earth's magnetic field. This experiment, suitable for a field trip, involves several abilities, such as modeling the magnetic field of power lines, looking up reliable information and estimating non-easily accessible quantities.

We present a critical analysis of the classical approaches to energy subjects, based on the work-energy theorem and the conservation of mechanical energy proposed in the courses of the first years of tertiary education. We show how these approaches present a series of inconsistencies and errors that are a source of conceptual difficulties among students. We then analyze a modern treatment of mechanical courses based on the results of research in physics education over the last 40 years. We place special emphasis on the principle of conservation of energy as one of the fundamental principles of nature, prioritizing the concepts of system, surrounding, and energy transfer and transformation.

The attitudes and beliefs of teachers and future physics teachers about epistemological aspects of Physics play a very important role in teaching the discipline. In this paper, after describing some of the most important results reported in the literature, we present the main results of the implementation of the CLASS test on attitudes and beliefs to hundreds of student and physics teacher in Uruguay. The results corresponding to the teaching students are similar to those who choose careers with an emphasis on Physics and Mathematics and, in turn, are clearly below those presented by professors and researchers. We highlight then the need to make explicit the issues related to epistemological attitudes and beliefs in our classes.

[ILLUSTRATION OMITTED] Mobile devices have become a popular form of education technology, but little attention has been paid to the use of their sensors for data collection and analysis. This article describes some of the benefits of using mobile devices this way and presents five challenges to help students overcome common misconceptions about force and motion. We've used these challenges--and the apps we created to go along with them--in our physics classes but have also found them useful in environmental science, chemistry, and biology classes as well. Using mobile devices in science Though U.S. science classrooms have used smartphones for data collection (Huffling et al. 2014; Heilbronner 2014), the international education community appears to have used them longer, having produced several lab ideas relevant for high school physics teachers in the United States (Kuhn and Vogt 2013; Barrera-Garrido 2015; Monteiro et al. 2014; Science on Stage Europe 2014; Gonzalez et al. 2015). Many of the apps involved use a smartphone's accelerometer, a sensor particularly well suited for teaching concepts of force and motion and cause and effect (Figure 1, p. 34; Monteiro, Cabeza, and Marti 2014; Tornaria, Monteiro, and Marti 2014; Vieyra and Vieyra 2014). The accelerometer is a micro force meter using small pieces of silicon that move in response to changes in orientation (see box). Students can use apps that use this sensor to measure linear acceleration and compare different types of motion, including constant velocity, linear acceleration, and centripetal acceleration. Knowing the mass of the mobile device allows them to measure its net force using Newton's second law, [F.sub.net] = ma, as well. Research shows that students struggle conceptually with the relationship between force and motion and especially with the concept of centripetal force as inward directed. Research by Hestenes, Swackhamer, and Wells (1992) on the Force Concept Inventory (FCI) shows that students typically gain only 24% to 42% on the FCI after traditional instruction involving lecture and cookbook labs. This suggests a need for more engaging instructional strategies. Mobile devices allow students to graphically model physical relationships (Arizona State University 2015) and to collect data outside the classroom, such as in the field or at home, so students can better see and understand science concepts in contextualized, relevant environments and improve their skills in science and engineering practices as described in the Next Generation Science Standards (NGSS Lead States 2013) (see box, p. 38; ISTE 2007). Data collected in environments such as these are typically big, "messy," and more realistic than that collected in the lab and thus present increased opportunities for learning and engagement. [ILLUSTRATION OMITTED] [ILLUSTRATION OMITTED] How to use mobile devices inside and outside the classroom Below are challenges we have used with students in regular introductory algebra-based physics courses around the world. Note that many schools still restrict the use of personal mobile devices in the classroom, so consult school administrators before starting. Discuss with students mobile device etiquette, including, if appropriate, that devices be screen-down during teacher-directed activities or class discussions. Also remember that any new technology in the classroom takes time to learn. Once learned, however, mobile devices can speed up data collection. Allow students time to explore what data their mobile devices can collect and what manipulations change the data collected. Students should investigate where the x, y, and z planes are on their devices (Figure 1) and how they are represented graphically. Students must understand what the device is measuring, and, if appropriate, how the internal sensors work (see box, p. 33). Students complete the five challenges presented on the following pages. …

The shape of liquid surface in a rotating frame depends on the angular velocity. In this experiment, a fluid in a rectangular container with a small width is placed on a rotating table. A smartphone fixed to the rotating frame simultaneously records the fluid surface with the camera and also, thanks to the built-in gyroscope, the angular velocity. When the table starts rotating the surface evolves and develops a parabolic shape. Using video analysis we obtain the surface's shape: concavity of the parabole and height of the vertex. Experimental results are compared with theoretical predictions. This problem contributes to improve the understanding of relevant concepts in fluid dynamics.

In the last years, numerous Physics experiments using smartphone sensors have been reported in the literature. In this presentation we focus on a less-explored feature of the smartphones: the possibility of using (measure and register data) simultaneously with more than one sensor. To illustrate, in the field of mechanics simultaneous use of the accelerometer and gyroscope (angular velocity sensor) or in optics experiments synchronous use of the ambient light and orientation sensors have been proposed. Indeed, this is a characteristic that simplifies experimental setups allowing to see through the physics concepts and, last but not least, reducing the costs.

The spatial dependence of magnetic fields in simple configurations is an usual topic in introductory electromagnetism lessons, both in high school and in university courses. In typical experiments, magnetic fields are obtained taking point-by-point values using a Hall sensor and distances are measured using a ruler. Here, we show how to take advantage of the smartphone capabilities to get simultaneous measures with the built-in accelerometer and magnetometer and to obtain the spatial dependence of magnetic fields. We consider a simple set up consisting of a smartphone mounted on a track whose direction coincides with the axis of a coil. While the smartphone is smoothly accelerated, both the magnetic field and the distance from the center of the coil (integrated numerically from the acceleration values) are simultaneously obtained. This methodology can be easily extended to more complicated setups.

The dynamics of a traditional toy, the yoyo, is investigated theoretically and experimentally using smartphone' sensors. In particular, using the gyroscope the angular velocity is measured. The experimental results are complemented thanks to a digital video analysis. The concordance between theoretical and experimental results is discussed. As the yoyo is a ubiquitous, simple and traditional toy this simple proposal could encourage students to experiment with everyday objects and modern technologies.