In this experiment we have first determined the focal length of an equiconvex lens. We have observed that a real image can be formed by the lens on the same side of the source if the source is sufficiently strong. This is due to the reflection from the concave surface of the lens. We have measured these image distances for different object…

We propose a laboratory experiment on the quantitative study of the normal dispersion of light. A triangular isosceles prism made of flint glass TF3 is used as the object of study, and we describe a simple and affordable device for observing and photographing the dispersion spectrum on a smartphone. A possibility of the quantitative investigation…

Data from the Kepler satellite were analysed using the Mikulski Archive for Space Telescopes database. With the participation of 53 students, we determined the parameters of the HAT-P-7b (Kepler-2) exoplanet system (transit duration, planet-to-star radius ratio, orbital period, semi-major axis and star mass). We used approaches that are easy to…

Circular motion changes the perception of up and down. For a skater, the need to lean in towards the centre of an arc constitutes an embodiment of centripetal acceleration. This paper presents a discussion between a physicist and a high-school science teacher without previous physics studies at university level. The discussions started as part of…

A simple measurement of the refractive index of a liquid has been performed using a spherical lens. This lens is a spherical shape flask containing the liquid under study. Parallel pointer laser beams are directed to the lens to obtain the back focal length of the lens. The focal point is determined visually or using the Tracker software to…

We have added two improvements to a self-luminous LED stroboscope (a flashing point-like projectile developed for introductory mechanics): downsizing by replacing heavy and risky batteries with a compact and safe capacitor of several Farads (a so-called Super-C) and wireless control via ordinary IR (infrared) communications. Consequently, the…

Collisions are a key topic in physics and engineering education. An experiment with multiple body one-dimensional collisions is presented, aiming to measure relevant physical quantities by tracking the motion of the system of particles during the collision. Relations between different physical quantities can be explored in the experiment, such as…

We demonstrated the fabrication of a low-cost and high-resolution papercraft smartphone spectrometer and characterized its performance by recording spectra from gas discharge lamps. The optical design and a lab-made narrow slit used in the fabrication led to fine images of the slit on the image sensor, resulting in high spectral resolution. The…

Huygens' principle in which every point on a propagating wave acts like a point source of radiation is a foundation principle of physics. Normally, Huygens' principle is demonstrated by passing a wave, for example a water or light wave through an aperture comparable in size to the wavelength. In this paper, an experiment is described in which a…

We designed and tested a 3D motion tracking system which displays acquired and derived data using augmented reality. This setup, based on a virtual reality headset and its controllers, is a relatively low-cost, high-precision, six degrees of freedom, high-speed, multiple-objects tracking device. This apparatus proves to be a very high-quality…

Pinhole camera photography is explored using a set of entomology pins due to their known pin diameters and availability in a variety of sizes. A procedure to prepare removable-lens digital cameras for pinhole photography is described. A video is included showing a set of ten insect pins and how to fit the camera with pinhole apertures. Formulas…

In this paper, we present a physical modeling activity whose objective is to allow students to determine the differences between a disk and a sphere using pure scientific criteria. Thereunto, we reproduce the Sun-Earth-Moon system with low-cost materials and compare the illumination effects on the Moon considering two possible shapes for it (a…

Measuring the 3D position at any time of a given object in real-time automatically and well documented to understand a physical phenomenon is essential. Exploring a stereo camera in developing 3D images is very intriguing since a 3D image perception generated by a stereo image may be reprojected back to generate a 3D object position at a specific…

Water can exhibit many different colors due to a variety of physical properties. Here, we focus on some observable colors within very pure freshwater. We only treat the absorption of light due to electronic and ro-vibrational excitations and scattering due to refractive index fluctuations of the water and the respective consequences for the…

For conducting laboratory experiments on Fresnel diffraction, the use of a simple point light source from an LED and the application of a modern smartphone for photographing the diffraction patterns are proposed. The developed devices allow the experiments to be carried out under normal laboratory lighting.