In times of the explosion of distance learning, because of emergency due to the pandemic, smartphone sensors and cameras are extremely valuable for teachers as they allow students to perform significant experimental activities in their own homes. The open-source software Tracker can be used in combination with the smartphone camera to perform measurements not only of mechanics activities, but also of optics. In the latter case, it is not always easy for students to understand how the pixel brightness which can be inferred from the taken photos are related to actual physical light intensity. In this paper we present a simple experiment to verify the exponential decay in the intensity of light going through successive sheets of a material (the Lambert law) with two different methods, i.e. using either the smartphone light sensor or the smartphone camera and Tracker. Besides its theoretical significance, the experiment constitutes a useful tool for calibrating the camera/Tracker combination to use it for different experiments.

In this paper we present an experiment aimed at investigating the thermal radiation law. The spectrum of a filament light bulb is acquired at different temperatures using a low-cost grating spectrometer based on a smartphone camera, while the measurement of filament temperature is obtained indirectly from the temperature dependence of the filament resistance. Two different methods for measuring the light intensity are tested: one is based on the use of the ambient light sensor of a smartphone, the other on a home-made grating spectrometer coupled with the smartphone camera. We observe a good agreement of the experimental data with the theoretical predictions of the Planck distribution in the limit of the Wien approximation restricted to the wavelength range characterizing the response of the smartphone light sensor and camera.

Arduino and Smartphones have been used since 2021 in a class of practicals held at Sapienza Università di Roma, to train physics undergraduates in laboratory activities. This paper briefly describes the organisation of the activities and report about the results of questionnaires administered to participating students before and after the course.

We describe an activity developed as laboratory at home during the pandemic period by which it is possible to investigate numerically and experimentally a harmonically driven pendulum with a variable frequency. We realized a prototype using LEGO® bricks and EV3 motor. Because the pendulum undergoes large amplitude oscillations, the motion has been studied by implementing the non-linear numerical model in Python. Students can acquire the experimental data with the software of video analysis and compare them with the numerical model. This approach allows to integrate, at varying levels of complexity, computational and experimental skills into the laboratory practice. The activity also allows a connection with the recent topic of gravitational waves detectors that use pendulums in cascade, as mechanical filters to attenuate the seismic noise.