Smartphone sensors and video analysis: two allies in the physics laboratory battle field

Abstract

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 opportunity to discuss not only concepts related to the specific experiment but also with the experimental and numerical aspects including their pros and cons.

Simple physics behind the flight of a drone

“…In our case, the maximum ascent speed reported by the manufacturer was 6 m s −1 which agrees very well with that obtained numerically as it can be seen in the figure. In case of having a large and clear space it is also possible to supplement these results with video analysis [10].…”

A home-lab to study uncertainties using smartphone sensors and determine the optimal number of measurements

“…The use of smartphone sensors has been incorporated in Physics laboratories in all the fields, see for example [5,6,7]. Worth mentioning characteristics of modern smartphones are the ability to measure simultaneously with more than one sensor [8] or supplement the data with video analysis [9]. A very important advantage is that students usually have smartphones and can therefore conduct experiments at home (see for example [10,11]).…”

The harmonic driven pendulum as a teaching example of integration of laboratory and computation

“…There is growing evidence that activity focusing on skills can be more effective than lab activity focusing on reinforcing concepts [10]. The activity we propose here can be positioned within this line of research, allowing to integrate, at varying levels of complexity, computational and experimental skills (with the use of video analysis [11]) into the laboratory practice. The introduction of computation elements can in fact help students to learn physics in a more creative and exploratory way [12,13] and it is also a skill highlighted in the AAPT Lab Recommendations and AAPT Conference Report (2019) [14,15].…”