The reflection and refraction of light are more familiar to students than the reflection and refraction of sound. Reflection and refraction that occur during the transmission of sound waves are common phenomena in everyday life but are often difficult to understand during actual learning. In this study, we developed a sound reflection and…

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 propose an experiment in which the sound of a drumroll is recorded and analysed according to a simple mechanical model in which the inelastic restitution coefficient of the collision between the stick and drum surface, as well as the ongoing kinematics of the drumstick, are considered. The agreement shows that this model is well suited for…

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…

Kundt's tube is a popular experiment commonly used in schools, in which standing sound waves are made visible inside a glass tube. A fine powder is stirred up in areas of high sound particle velocities, so that one can measure the wavelength of the sound waves by examining the patterns created. In this way, the 'invisible' can be made visible.…

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…

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.…

In this study, we visualized the superposition principle of sound waves in a both-closed-end (BCE) resonance tube. The resonance tube is constructed using an acrylic tube with 2.64 cm internal diameter and 150 cm length, polystyrene beads to illustrate the positions of displacement nodes and antinodes and two identical detachable speakers as…

The fundamental air cavity mode (A0) of a violin was investigated from the viewpoint of its dependence on the opening area and shape by using holed sheets of paper. The dependences of the frequency response of the A0 cavity mode on the shape, opening area, and orientation of the openings were observed. It was also demonstrated that the change of…

Laboratory report assignments for non-major and introductory classes can be challenging because the students are unfamiliar with the type of technical writing required and the subject matter. These issues for the student make the grading for the instructor difficult and time consuming. Determining the level of detail to require, the format, and…

The resonance phenomenon is widely known in physics courses. Qualitatively speaking, resonance takes place in a driven oscillating system whenever the frequency approaches the natural frequency, resulting in maximal oscillatory amplitude. Very closely related to resonance is the phenomenon of mechanical beating, which occurs when the driving and…

Experiments using smartphones allow for teaching physics concepts in a fun and engaging way and including interdisciplinary approaches. The exploratory character of the experimental activities, along with the smartphones' embedded technologies, when applied in the high school classroom, also has the potential to awake the students' intrinsic…

We developed a simple device to teach the concept of pH to visually impaired people through an experimental approach. An interface between a glass electrode and an open-source electronics platform based on easy-to-use hardware and software (Arduino Uno) was designed using an operational amplifier of ultralow input current. A headphone connected to…

Resonance is an ubiquitous phenomenon present in many systems. In particular, air resonance in cavities was studied by Hermann von Helmholtz in the 1850s. Originally used as acoustic filters, Helmholtz resonators are rigid-wall cavities that reverberate at given fixed frequencies. An adjustable type of resonator is the so-called "universal…

In this study we constructed a special three-in-one resonance tube for a harmonic series sound waves experiment. It is designed for three different experiments: both-open-end, one-closed-end and both-closed-end tubes. The resonance tube consists of a PVC conduit with a rectangular hole, rubber tube, plastic stopper with an embedded microphone and…