With the development of digital technology, plentiful sensors are embedded in the smartphone, which makes it a valuable tool for teaching elementary experimental physics. For instance, the magnetic field sensor of the smartphone has been used to measure gravitational acceleration by measuring the magnetic pendulum's oscillation period. The…

We propose a method to measure the speed of sound in air using a motion detector. The experiment is based on the principle of a motion detector used to measure distances. This device measures the time of flight of alternating ultrasonic waves between the observer and the target. By assuming a fixed speed of sound, the time of flight can be…

It has now been over 100 years since Heinrich Barkhausen published his description of a crackling sound heard when a piece of iron is magnetized inside of a coil wired to a set of headphones, and this phenomenon provided evidence for the theory of magnetic domains. Traditionally, this effect is performed as a demonstration by connecting the coil…

The integration of physics, music, and mathematics has long been used to increase students' interest and motivation in these subjects. For example, previous articles in this journal have shown how to teach physical concepts in a musical context, use a smartphone to check the resonant frequencies of whistles, use a smartphone to examine the spectra…

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…

Observing the bouncing of a marble on a table is a rather common experience. The tic-tac sound of the rigid ball, nevertheless, carries quite a pleasant surprise. In fact, by measuring the total time of bouncing [delta]t, the coefficient of restitution can be estimated. As is well known, in an inelastic collision the kinetic energy is not…

The determination of the speed of sound in air is a classical experiment, usually performed with a resonance tube apparatus. The measured value can be checked against Eq. (1), which describes the temperature dependence of the speed of sound in dry air. A modern implementation of this speed of sound investigation uses an Arduino Uno microcontroller…

The typical sound of George Lucas' laser blaster in the "Star Wars" series is well known. What does a laser blaster in "Star Wars" sound like, and why? Here we show a simple way to produce this sound by using low-cost lab material, like a spring or a Slinky. Building on the work of Crawford, who analyzed the sound of a Slinky…

Like many other universities, Musical Acoustics is offered at our school as a lab-based course fulfilling general science requirements for non-majors. The course has been team-taught by a physics professor and music professor since its earliest inception and, by far, the most popular unit explores room acoustics through a variety of activities and…

Science labs should promote reasoning that resembles the work that scientists do. However, this is often not the case. We present a lab in which students strive to find out which of two models best describes a physics experiment. The quantification of measurement uncertainties--another topic that is often neglected in high school…

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…

We present a simple experiment that allows us to demonstrate graphically that the intensity of sound waves is proportional to the square of their amplitude, a result that is theoretically analyzed in any introductory wave course but rarely demonstrated empirically. To achieve our goal, we use an audio signal generator that, when connected to a…

We describe an educational activity that can be completed with mobile media devices in order to understand the working principle of a pair of tuning forks, from the Historical Collection of Physics Instruments of the University of Palermo, and how they were used to explain acoustic interference and beats with the Lissajous optical method. This…

The construction of a linear speaker array, which emits coherent sound radiation from multiple sources, is described. The device is an improvement over the two-speaker systems for demonstrating wave interference effects. The operation of the array is demonstrated with example data.

A new device for teaching the physics of sound, specifically demonstrating the wavelengths of standing sound waves, is here described. I define a "Lincoln's Tube" as any hollow tube that uses lights (LEDs typically) to demonstrate the presence of sound standing waves. The name is chosen intentionally to recall a Ruben's Tube or a Kundt's…