We present a modernization of the undergraduate physical chemistry laboratory experiment for determining the speed of sound in various gases from resonant frequencies in a spherical resonator. The resonator (schematic IR = 7.5 cm) is constructed by 3D printing with eco-friendly poly(lactic acid), a commercially viable alternative to traditional…

The formation of chemical patterns is in general difficult to control due to the random diffusive motions of the reacting chemical species in solution. In this paper, we present a new method using audible sound to control the formation of chemical patterns obtained in blue bottle experiments. The waves generated on the surface of the solution by…

To study the absorption of ultrasound in plexiglas we propose to use gadgets that are available to each student: an ultrasound humidifier, a liquid crystal display of a pad, a polaroid analyzer, a digital camera, a multimeter with thermocouple, and a stopwatch. These devices allow us to visualize a region in plexiglas where ultrasound is absorbed…

We describe here a low-cost experiment for introductory physics students where they compare the physical properties of aluminum and steel by means of cantilever oscillations. This, in turn, allows the students to improve their physical intuition about these materials. Further, the students can apply their physics and mathematics knowledge and…

We present a novel method for demonstrating the physical principles of ultrasound imaging at a level suitable for educational programmes up to the university level, using a simple mechanical model that is very inexpensive and accessible to a broad variety of educational institutions. The method revolves around the use of one or two steel springs…

We present an experiment designed to study standing waves in a tube with one closed end. Two smartphones are used, one to emit a sound signal with a chosen frequency and another equipped with a microphone to detect the sound pressure level inside the tube. Due to the finite diameter of the tube, the standing wave node (or antinode) appears…

By building a schlieren optical system, the visualization of a 40 KHz sound wave is realized. By using the schlieren system, the demonstration of acoustic reflection, interference and diffraction can be easily realized. At the same time, the visual acoustic field provides another simple way for the measurement of sound velocity. In this paper, the…

Various experiments on vibrating gas columns and on frequency measurements with glasses and pipes have been presented in recent years in the "iPhysicsLabs" column. The determination of the sound velocity in different gases by measuring the sound running time has also already been proposed in an earlier paper. This article now adds…

Photoacoustic imaging is a state-of-the-art technique that combines light excitation with ultrasound generation via the photoacoustic effect. Since sound waves at clinically relevant frequencies undergo minimal perturbation as they pass through the body, photoacoustic imaging is ideal for deep-tissue imaging applications in vivo. Despite its…

This article presents the study of Fourier series experimentally, using the "ExpEYES"-17 kit in a different way. This familiar undergraduate experiment has been performed for teaching online laboratory classes when face-to-face classes were not possible, due to the "COVID"-19 pandemic. We chose parabolic and sawtooth waveforms,…

Sound is an interesting topic for physics lessons at all ages. However, it is difficult to illustrate this ubiquitous phenomenon and many models do not adequately represent the properties of sound and thus promote unwanted conceptions. The experiment presented here avoids this by visualising sound itself with the help of the schlieren technique.…

The purpose of this study was to develop a modern experimental apparatus using an Arduino with LabVIEW instead of the classical experiment. The wavelength of the sound was determined using the resonance of an air column. The smartphone app was used to generate the desired frequencies. A sound intensity and ultrasonic sensor was used to read the…

Similar to how stealth materials were developed to reduce the radar wave energy returning from an aircraft, here we explore a low-cost laboratory demonstration that uses similar principles to prevent detection of an object by an ultrasonic sensor. This demonstration setup can be used as a starting point to encourage students to explore the surface…

A phone emitting sound of a fixed frequency is sliding on an inclined plane and approaching a second phone kept at the bottom of the plane. The detected frequency versus time data by the second phone are used to calculate the acceleration of the sliding phone. The primary objective of this paper is to calculate the sliding friction between the…

The acoustic resonance in four glass Helmholtz resonators with diameters of 70, 52, 40, and 32 mm was detected in the frequency range of 360 to 1700 Hz using the simple experimental setup presented in this paper. The measured amplitudes of acoustic pressure required correction since the sound pressure amplitude of the loudspeaker used was not…