Table of contents

Modern instruments use sensors, analogue and digital electronics, and digital processing to measure almost any kind of physical quantities. Arduino is a very useful and widely used platform to build such systems in a school environment. Since it has analogue voltage inputs, it can be used as a digital voltmeter or even as a chart recorder. However, the ways of ensuring the required level of accuracy or just the right estimation of accuracy are often unknown or misunderstood. In this paper we try to fill this gap to aid reliable school experimentation.

The flight of a spinning rugby ball is difficult to describe mathematically but easy to observe experimentally. The flight can be simulated by dropping an egg into a water tank and observing or filming the outcome. Differences between a spinning and a non-spinning wooden egg are presented as supplementary videos.

The oscillation frequencies of a double pendulum are derived by extending the usual calculation for a single pendulum. Experimental results are presented as supplementary videos.

The overall efficiency of a reversible thermodynamic cycle comprising steps around the periphery of back-to-back Carnot cycles is equal to the efficiency-weighted average heat-energy inputs taken over all of the cycles. A proof of this assertion is straightforward and brief enough to be suitable for classroom presentation.

The sound of impacts made by the two outermost balls in a Newton's cradle were recorded with a smartphone sound sensor. As a time series of sound pressure levels, the data made it possible to obtain the period of the identical pendulums. Hence the determination of the acceleration due to gravity. The result, on average, g = 9.99 m s⁻², is close enough to the locally accepted value of 9.78 m s⁻² for instructional purposes.

In the initial topic in basic physics in school and college, the concept of analysing a measurement error needs to be understood by students. This paper proposes the use of various sensors on smartphones for statistical error analysis which usually uses the classical method with repeated measurements. The smartphone sensors used were light, acceleration, and magnetometer sensors. The data from the sensor recording fluctuations for 10 s were analysed for the simple statistical figures and error. The experiment used three different conditions, namely placing the smartphone on a stable table, holding it with your hand, and bringing it closer to a notebook that played a 650 Hz tones. The experimental findings, the experimental conditions (environmental and blunder), and the specifications of the instrument affect the error. Students also can tell that the sensor takes repeated measurements so that it shows fluctuation data. This research contributes to offering the use of the latest technology, namely smartphones, for statistical error analysis for physics students.

We consider the cases of a beam hanging from four and three strings. In addition to the static equilibrium equations, these statically indeterminate structures can be easily resolved for the unknown tension forces with only using Hooke's law.

The hFE of a transistor, or commonly known as the hybrid parameter forward current gain, is one of the important factors that characterizes the working of a transistor in any circuit. So designing such an experiment with readily available materials would help STEM students gain more intuition about the working principle of transistors in general. In this experiment we had used an Arduino UNO microcontroller along with some resistors and by using Ohm's law we were able to deduce a formula for the hFE (hybrid parameter current gain) of any npn transistor used in the circuit, just by measuring the voltages across the input and output resistors used along with the transistor in a common emitter configuration.

We present a study of the slowing of sound by a corrugated drainage pipe that serves as a straightforward project lab investigation for undergraduate students.

If an egg rolls end over end along a horizontal surface at sufficient speed it will become airborne. A similar effect occurs if a person walks fast enough. The person then becomes airborne and both feet lift off the ground in a running stride.

An easy circuit for measuring the power of a solar panel in physics classroom by using the microcontroller Arduino will be introduced in this article. The measured data is transferred via Bluetooth to the smartphone app 'phyphox' where it is displayed graphically. The circuitry enables measuring the power of a solar panel in different situations of light intensity. Several model experiments for students will be described.

Chaotic phenomena are not part of standard curricula, although this subject offers several interesting aspects which can help students better understand basic features of science. A central observation is that even simple physical systems, if chaotic, are unpredictable, just like the weather. We present the principles applied when developing a freely available short interactive material and outline the material itself. By the means of this material students can become acquainted with the elements of chaos science and also learn that the regular motions taught in physics lessons are the exceptions rather than the rule since a slight modification of the set-up (e.g. letting the suspension point of a pendulum move periodically) converts the motion to chaotic. The material can be used in both classroom and online teaching.

An experiment is described where a billiard ball and a golf ball were projected with backspin on a horizontal surface to measure the transition from sliding to rolling. During both phases, the torque on the ball is affected by an offset in the line of action of the normal reaction force.

Although learning about Nature of Science (NOS) promotes a variety of important outcomes, teachers often lack suitable activities for younger students to effectively address NOS. In this article I elaborate on a NOS activity developed for a teacher professionalisation workshop. The activity is suited for younger students as well, where clear links are made between elements of the activity and how science works.

The drag effect on a falling ball caused by air is a conventional subject in the most well-known textbooks of classical mechanics and fluid dynamics. Further, there are some papers that employ video analysis to track objects movements in the air making it possible to obtain position data as a function of time and its graphs. However, none of them addresses the case of a ball thrown downwards, maybe because this situation is neglected by textbooks or probably due to the experimental difficulty to perform this kind of launch manually. In this paper, both the fall and the vertical launch down of five different Styrofoam balls are filmed with an ordinary smartphone camera and analysed by using the free software Tracker. The position and velocities graphs depicted clearly the air drag effect on the ball's movements. The entire raw data are compared with a theoretical model and therefore terminal and initial velocities can be extracted as adjusted parameters from simple mathematical fits. The Reynolds number and the drag coefficient calculated for each ball agree with those found in the literature.

The purpose of this study is to consider Superman's acts against impulse–momentum and conservation of momentum principles. Superheroes as fantasy fiction characters attract the attention of not only children and teenagers but also adults. Superheroes can be useful in explaining a phenomenon, as well as overcoming conceptual difficulties that may occur in students. Superman is a superhero who often challenges the impulse–momentum principle and conservation of momentum. Therefore, he may be the best superhero to use when talking about momentum. This context gives educators an opportunity to motivate students.

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.

The net force and net torque exerted by a uniform magnetic field on a rigid current-carrying loop are discussed in all introductory physics textbooks. A notable omission, however, is the discussion of the equilibrium of a deformable current-carrying loop in a uniform magnetic field. In the article, we present such an analysis for the simplest case of a quadrilateral current-carrying wireframe placed in a uniform magnetic field. We discuss the area-maximizing effect of the field on the frame and use the conditions of translational and rotational equilibrium to establish the 'cyclicity' of the latter as well as the uniformity of the magnitude of the contact forces acting at its joints.

We have investigated the motion of water flow through glass tubes of different shapes by calculating the value of the Reynolds number denoted as ${\text{Re}}$. We know that at a given flow rate the value of ${\text{Re}}$ determines the type of flow being classified as laminar, transitional or tubulent. The dependence of ${\text{Re}}$ in different configurations of glass tubes as well as on temperature is investigated. The apparatus for the experiment is designed in the undergraduate laboratory and the conventional method of measuring the flow rate using a dye for detecting the type of flow is used.

A digital learning-teaching environment is introduced in which undergraduate students are challenged to connect the basic physical concepts of oscillation, buoyancy and data analysis via an authentic experiment. The damped oscillation of a cylindrical body swimming upright in water is measured via the MEMS acceleration sensor of a wireless MCU SensorTag. The data are recorded with the app phyphox on a smartphone or tablet. The theoretical oscillation period and the experimentally determined periods obtained via different data analysis roots are found to agree showing an excellent theory-experiment interplay. The proposed experiment is suited for the physics home lab e.g. under the current pandemic situation or for open university courses as well as for physics lab courses.

This research aimed to design an instructional module to teach light diffraction by a grating to secondary students applying a science, technology, engineering, and mathematics (STEM)-integrated approach. Based on this approach, instructional management integrated the disciplines of physics and mathematics with engineering design process principles, while information searches, assessment, and evaluation drew on technology. The module involved working out a solution to the real-world scientific problem of constructing a spectroscope in the environment of cooperative learning. Upon completion of the module, the students were expected to demonstrate a thorough understanding of light diffraction by the grating as well as problem-solving skills. To evaluate its effectiveness, the module was trialed on thirty 11th grade students in a Thai school in Pathum Thani, Thailand. The findings revealed that the implementation of the module enabled the students to achieve a statistically higher post-test score than that for the pre-test at the significance level of 0.05. As a result of the module, the students also exhibited a high level of academic development, as indicated by the class normalized gain of 0.82. Finally, the module was perceived by the students as being suitable for their level, offering them a chance to apply classroom knowledge to authentic problems and hence accumulating their hands-on experience, enhancing their problem-solving skills through the application of the engineering design process, and improving their team-working ability.

A practical experiment is described to estimate the distance to a star using simple equipment, suitable for secondary or undergraduate students. The brightness of the star is visually matched to a miniature filament lamp, and its distance inferred from the inverse square law. Students gain an appreciation of astronomical units and practice in manipulating powers of 10. By additionally applying knowledge of the H-R diagram and black body radiation, accuracy can be improved to one order of magnitude.

This study focuses on the experimental demonstration of the definition of kelvin using a triple point of water (TPW) cell and estimates the measurement uncertainty. The first part of this article is to construct the measurement setup and perform the measurements. The second stage is related with the calculation of uncertainty according to guides to the expression of uncertainty in measurement. The experiment in this study can be a practical and convenient method to show the unit as the fraction 1/273.16 of the thermodynamic temperature of the TPW, 273.16 K.

Fermat's principle states that a light ray refracted across different media will traverse the fastest path as the physics for Snell's law. A geometric proof of Fermat's principle will be demonstrated as an intuitive approach to learn high school geometry and physical optics. It will be proved explicitly by showing that all alternative paths need more traversal time to complete their journey.

In this work, we have developed an alternative device composed by an Arduino board and an INA219 sensor to experimentally obtain the mathematical formulas describing the charge and discharge of the capacitor for educational proposes. We have obtained excellent agreement between theoretical prediction and experimental measurements. The INA219 DC sensor can measure direct current up to 26 V/3.2 A with a maximum error accuracy of 1%. The device makes it possible to follow the temporal evolution of the voltage and the current at a capacitor's terminals. This platform can provide an alternative way for educational use compared to the expensive laboratory equipment (oscilloscope, voltmeter, generator). Indeed, we think that the presented device can play a dominant role in teaching and learning electricity courses in secondary schools due to its low cost, small size, reliability in measurements and good level of accuracy.

We present a sequence of two physics experiments, designed for use with secondary students, which investigate the specific heat of sand, both qualitatively and quantitatively, without a calorimeter. We use two LM35 temperature sensors and an Arduino prototype board for data acquisition. The results are good and allow teachers to discuss the behaviours of water and sand in the heating and cooling processes. Our proposals are suitable for use in the teaching of high school students and lead to meaningful learning about this physical property.

This paper demonstrates the use of a smartphone as a low-cost multi-channel optical fibre spectrophotometer suitable for physics laboratory classes. A custom-designed cradle and structure support were fabricated using 3D printing. The plastic optical fibres were arranged and inserted into the hole of the cradle to guide the light to the rear camera of the smartphone. Here, we describe the multi-channel optical fibre-based smartphone spectrophotometer for measuring the spectra of different LED colours.

Experimental teaching is essential for a good understanding of science, especially on Physics. Practical activities play an important role for engaging students with science, mainly when they interact directly with equipment, collect experimental data with computers and/or use interactive software for data analysis. In this work, we present the use of low-cost mini-robots as an 'object-to-think-with' for teaching and learning with technology. The activity concerns programming the robots to make them run in circular paths, record videos of their trajectories and analyse them with Tracker Software, to boost the study of Astronomy contents. This kind of practical activity develops multiple skills in students and is usually very well accepted because it involves robots, programming, manipulating technology and for raising topics that are difficult to understand in real-life observations, making them cognitively accessible to the vast majority of students. In this practical activity, students are asked to create the robot programming code and make a video recording (with a smartphone) of the robots' trajectories, mediated by the teacher, who assists in the construction of the experimental activity and analysis of the data obtained. The results will allow students to understand Kepler's laws of planetary motion and why some planets seem to have an apparent retrograde motion as seen from the Earth, a problem that arose in IV BC and was only officially solved by the Copernicus heliocentric model, published in 1543, the year of his death.

Active learning yields better learning outcomes than traditional, lecture-based teaching. Common approaches in large lecture courses are activating elements during the lectures and warm-up activities using online learning environments. However, implementing warm-up exercises, on which students work on by themselves makes formative feedback increasingly important. We have studied students' views on warm-up online exercises, focusing on the role of automated feedback. We compared two types of feedback: feedback which guided the student towards the correct answer and feedback that guided the student towards the correct reading materials. We have also examined the correlation between students' views on the exercises and learning outcomes, as measured by exercise and exam points. The exercises were administered with a Moodle-based system focusing on teaching and assessment using a computer-based algebra kernel. The study was conducted during the first introductory mechanics course in physics at the University of Helsinki. We concluded that the preferred type of feedback was dependent on the student, i.e. different students prefer different kinds of feedback. Importantly, the students who completed the exercises alone reported benefiting more from them, which shows that the warm-up exercises successfully extended support for students outside of classroom hours.

Physics teachers are often faced with the challenge of having to set up difficult experiments, or they have to consciously manipulate parameters in order to be able to demonstrate a phenomenon convincingly. Comprehensive laboratory courses are standard procedure in any study program for prospective physics teachers. However, many students, even after completing standard laboratory courses, show difficulties in standard experimental situations, such as measuring an electric current. We report on a new seminar concept for students in physics teacher study programs. This concept is based on the current state of research in physics education, on the teachers' professional competences, and on the modelling of experimental competence, justifying its embedding in teacher training. We present first results of a pilot study carried out to evaluate the seminar.

This study presents an experimental method that illustrates and quantifies the Doppler-effect phenomenon. Two stages of the experimental process were carried out. First, a simplified ripple tank was used to depict the Doppler effect, and the whole experiment was recorded by a digital camera. Second, video analyses of the recorded experiment were conducted to quantify the Doppler effect. The experiment showed (a) that the Doppler-shift waves can be visualised clearly using the simplified ripple tank, and (b) that the observed number of waves in such an experiment is consistent with the theoretically expected number, with an error rate of less than 5%. This study proves that using a video-recorded ripple tank experiment to teach and learn the phenomenon of the Doppler effect can be highly efficient, because the method provides clear visualisation and accurate quantification of the Doppler effect.

In the violin, the fundamental air cavity mode (the A0 mode) is associated with the sound radiated by the f-holes. The dependences of the sound velocity of the A0 frequency on gaseous temperature and mass were investigated. It was found that the frequency of the A0 mode changed, depending on the molecular weight and the temperature of the gas filling the violin's body. From these results, it was deduced that a temperature change in the room in which musical instruments are played may be reflected in their tones. The measurement of the A0 modal frequency of a violin, focusing on the molecular weight and temperature of the gas, would be useful to students of physics to help in the understanding of sound velocity.

This paper demonstrates the use of a smartphone's sensors in recording experimental data for investigating the large angle of a physical pendulum. The smartphone (iPhone 5s) was attached to a beam to record simultaneously both the angular position and the angular speed of the beam oscillating about the pivot. The period and phase space of the oscillation were theoretically calculated and were compared with the experimental data. It was found that the experimental results agreed well with the theoretical calculations. We expect that this experiment based on a smartphone's sensors could be useful for physics teachers and encourage the interest of students.

Books: (Very) Small-scale Science for Young Scientists: Clare Thomson reviews 'Nano' by Dr Jess Wade

What Does Quantum Mechanics Really Tell Us About Our World?: Rick Marshall reviews 'Helgoland' by Carlo Rovelli

Only Connect: Rick Marshall reviews 'A Life on Our Planet' by David Attenborough

A Meditation on the Meaning of Life: Peter Main reviews 'Until the End of Time' by Brian Greene

The 'How' and 'Why' of Teaching Science: David Sang reviews 'Powerful ideas of Science and How to Teach Them' by Jasper Green

How does the comparative density of ice and water affect water levels as ice melts in different circumstances? This article attempts to demonstrate this.

Rod Cross (Phys. Educ.56 035017) has investigated the translational and angular accelerations of a rigid body rolling down a ramp inclined at angle Θ relative to the horizontal. The transition from rolling without slipping to rolling with slipping is explicitly included. Experimental results (obtained by digitizing movies of the motion of the object with reference lines drawn on it) are plotted as a function of Θ varying from 10° to 60° in 10° steps. In this Comment, the theoretical predictions for these accelerations are graphed over the continuous range of angles from 0° to 90°. The resulting curves have some features that are not visible in the experimental data.