Endoreversible thermodynamics is a theory for the (approximate) description of thermodynamic
non-equilibrium systems, which allows us to capture the ever present irreversibilities of real
processes. For instance in heat engines the dissipation due to…

The Euler–Bernoulli equation describing the deflection of a beam is a vital tool in structural and
mechanical engineering. However, its derivation usually entails a number of intermediate steps that
may confuse engineering or science students at th…

Energy conservation is a deep principle that is obeyed by all of the fundamental forces of nature.
It puts stringent constraints on all systems, particularly systems that are ‘isolated,’ meaning that
no energy can enter or escape. Notwithstanding…

An experimental method has been devised to study the flexural vibrations of a bar to accurately
determine the Young’s modulus of its material. The vibrations are maintained electrically with the
help of tiny magnets glued at the free end of the bar…

A simple experiment is described to measure the coefficient of rolling friction for a low bounce
ball rolling on a horizontal surface. As observed previously by others, the coefficient increased
with rolling speed. The energy loss due to rolling fric…

The approach to the treatment of mass in relativistic mechanics advocated in the article by Keith
Atkin in the January 2015 issue of Physics Education (2015 Phys. Educ . 50 46) conflicts with the
viewpoint promoted of many eminent physicists for over…

Solar current is an increasingly important aspect of modern life and will be even more so crucial in
the students’ future. Encouraging students to be the ‘toolmakers’ allows students to take ownership
of scientific investigations, as well as fo…

The aim of this research was to design a simple experimental device to see electric field force
lines using common components which are readily available in everyday life. A solution of baby oil
was placed in a plastic container, 4.5  ×  4.5…

This paper begins with an early measurement of the speed of sound in water. A historical overview of
the consequent development of SONAR and medical imaging is given. A method of measuring the speed
suitable for demonstration to year 10 students is d…

A simple capacitive cell for dielectric constant measurement in liquids is presented. As an
illustrative application, the cell is used for measuring the degradation of overheated edible oil
through the evaluation of their dielectric constant.

Description unavailable

If a person has ‘a problem’ to solve and knows the solution and just has to apply it (retrieve it
from memory and re-act), it is not a problem—it is a task; if a person does not know the solution
and has to create it—this is a problem. Using …

In my article (Featonby 2015 Phys. Educ . 50 641) a paperclip on a cotton thread was lowered towards
a string magnet, but what happened and why?

Creative learning is discussed with respect to a specific physics topic. A teaching example, based
on an apparatus that demonstrates the standard dynamo model of geomagnetism, is presented. It
features many of the basic physics concepts within the sy…

To increase the attention of students, several physics experiments can be performed at school, as
well as at home, by using smartphones as laboratory tools. In this paper, we describe a mechanical
model of the smartphone’s accelerometer, which can …

A technique is described for calculating the brightness of the atmosphere of the Earth that shines
into the Earth’s umbra during a total lunar eclipse making the Moon red. This ‘Rim of Fire’ is due
to refracted un scattered light from all the s…

In most secondary physics textbooks, waves are first introduced with examples of mechanical waves
because they can be illustrated by drawings and photographs. However, these illustrations are static
and cannot reflect the dynamic nature of waves. Alt…

In this paper, we present a low-cost method to study the Gay-Lussac’s law. We use a heating wire
wrapped around the test tube to heat the air inside and make use of a solid state pressure sensor
which requires a previous calibration to measure the …

What happens to a liquid in a swing or a loop? Accelerated motions lead to effects that may seem
surprising. Consider a liquid in a glass placed on a wooden triangle, in turn attached to a string
and moving fast in circle a vertical plane. The surfac…

What trajectory in the laboratory frame does a marble follow if it is held inside a freely rotating
pipe and then suddenly released so that it can slide frictionlessly outward along the pipe? A
previously published solution is only valid for a pipe o…

What happens when a large mass is placed between an impacting force and fragile item? This is
investigated using a nail, tree trunk and plastic cups.

We demonstrate how the form of a plano-convex lens and a derivation of the thin lens equation can be
understood through simple physical considerations. The basic principle is the extension of the
pinhole camera using additional holes. The resulting i…

Literature in Physics Education has shown that students encounter many difficulties in understanding
wave propagation. Such difficulties lead to misconceptions also in understanding sound, often used
as context to teach wave propagation. To address t…

Poggendorff showed experimentally, in the middle of the 19th century, that the weight of an Atwood
machine is reduced when it is brought to motion. His experiment has been revisited from time to
time, making use of instrumentation that reflects the t…

The ‘safety lamp’ invented by Humphrey Davy in 1815 utilised the cooling effect of metal gauze to
prevent the flame of a candle or oil lamp (essential for illumination in mines) from passing through
such a screen. It is therefore rendered unable …

The famous motto of the Lucky Luke comics series and its accompanying drawing are analyzed from a
physicist’s viewpoint. They provide useful pedagogical tools to discuss such aspects of relativity
as causality, the equivalence principle, gravitatio…

The surface gravity on Mars is smaller than the surface gravity on Earth, resulting in longer
falling times. This effect can be simulated on Earth by taking advantage of air resistance and
buoyancy, which cause low density objects to fall slowly enou…

This review presents an overview of the formulation, characterization and range of applications for
polymer nanocomposites. After explaining how material properties at the nanometre scale can vary
compared to those observed at longer length scales, t…

Working with a toy model whose partition function consists of a discrete summation, we introduce the
statistical field theory methodology by transforming a partition function via a formal Gaussian
integral relation (the Hubbard–Stratonovich transfo…

The article describes the use of elementary techniques in computer vision and motion photography for
the analysis of well known experiments in interactive instructional physics laboratories. We
describe a method for the automated tracking of the kine…

Basic explanations of the double slit diffraction phenomenon include a description of waves that
emanate from two slits and interfere. The locations of the interference minima and maxima are
determined by the phase difference of the waves. An optical…

Experimental and theoretical results are presented showing that a ball with a high coefficient of
rolling friction can roll to a stop when it rolls without slipping down an inclined plane. The rate
at which energy is dissipated is directly proportion…

We have performed an experiment in which we have determined the viscosity of air using the
Hagen–Poiseuille equation in the proper range of the Reynolds number (Re). The experiment is novel
and simple which students even at high school level can pe…

The magnetic field of the infinite solenoid is calculated using a new method. An infinitely long
charged line moving along a closed curve on the plane perpendicular to the infinite line will
generate an electric current and so the magnetic field of t…

An Eulerian/Lagrangian approach is used to calculate the physical forces acting on a spherical
bubble. Reynolds average Navier–Stokes (RANS) equations for the Eulerian approach are solved with a
finite volume scheme. The SIMPLE algorithm is utilize…

In this study, we investigated pre-service physics teachers’ mental models of light in different
contexts, such as blackbody radiation, the photoelectric effect and the Compton effect. The data
collected through the paper-and-pencil questionnaire (…

We describe a vacuum-based pressure-detecting capillary viscometer for the viscosity determination
of Newtonian fluids without known density. The viscometer operates on the principle that the
variation in air pressure of the vacuum vessel ##IMG##
[h…

Galileo asserted that the fall of bodies is independent of their weight. Whether or not he relied on
actual experiments, he explicitly argued in his writings that this fact could be proved by purely
logical reasoning. However, there is an important f…

Two methods for estimating Avogadro’s number from the observation of the daylight sky are presented,
both suitable for undergraduate students. One is very simple and based on simple naked-eye
observation, and the other exploits a common digital cam…

In this paper, a semiclassical approach is used to describe a kind of black-body which we will call
a matte black-body. Although the frequency energy density of a black-body is deduced using a
semiclassical method which includes the electromagnetic r…

Acceleration of a common car with with a turbocharged diesel engine is compared to the same type
with an electric motor in terms of kinematics. Starting from a state of rest, the electric car
reaches a distant spot earlier than the diesel car, even t…

The observation of diamond-like light spots produced by surface bubbles obliquely illuminated is
reported. The phenomenon is discussed in terms of geometrical optics, and an explanation is provided
attributing the effect to the astigmatism introduced…

We show that for the helium atom with electrostatic repulsion between electrons, the operators for
the z component and the square of the total angular momentum commute with the Hamiltonian, and
therefore quantum numbers M and L can be used to label t…

The aim of this mixed method study is to identify evaluation criteria for interactive e-books. To find answers for the research questions of the study, both quantitative and qualitative data were collected through a four-round Delphi study with a panel…

The concept of the massive, open, online course (MOOC) is not new, but high-profile initiatives have moved MOOCs into the forefront of higher education news over the past few years. Members of institutions of higher education have mixed feelings about …

Canada’s important areas of expertise in open educational resources (OER) are beginning to be built upon or replicated more broadly in all education and training sectors. This paper provides an overview of the state of the art in OER initiatives and open higher education in general in Canada, providing insights into what is happening nationally and provincially. There are growing examples of OER initiatives from several Canadian institutions offering free courses to Canadians and international learners. National open education initiatives include the federal government’s Open Data pilot project and the Council of Ministers of Education of Canada (CMEC) support for the Open Educational Resource Paris Declaration, as well as Creative Commons Canada. Regionally, the western provinces of British Columbia and Alberta are supporting OER as part of major open education initiatives.

Conducted in conjunction with an institute on open textbook adaptation, this study compares textbook evaluations from practicing K-12 classroom teachers (n = 30) on three different types of textbooks utilized in their contexts: copyright-restricted, op…

Massive Open Online Courses (MOOCs) came to prominence with Open Educational Resources Movement (OERM). It was based upon the idea of libre in removal of some permission barriers and gratis in removing the price barrier (Suber, 2008) in learning resour…

In China, microblogging is an extremely popular activity and is proving to be an effective mechanism to gauge perceptions about social phenomena. Between 2010 and 2015 Sina Weibo, China’s largest microblogging website, generated 95,015 postings from 62,074 users referencing the term massive open online courses (MOOCs), a method of online course delivery popularized in North America that has spread globally. Time series analyses revealed distinct patterns in the volume of postings during a four-year period, and subsequently by month, by week, and by the time of day. The volume of postings during the week, for example, peaked on Monday and declined daily to a low point on Saturday. Relative to maximizing learner engagement, the findings may provide insight to parties who deliver MOOCs to employ or test strategies on timing (i.e., time of year to offer/not offer a MOOC, time of week to release/not release new material, time of day to schedule/not schedule chat sessions). The paper also serves to demonstrate a mechanism to retrieve big data from social media sources, otherwise underutilized in educational research.

The idea of a Massive Open Online Course (MOOC) has attracted a lot of media attention in the last couple of years. MOOCs have been used mostly as stand-alone online courses without credits. However, some researchers, teachers, colleges, and universiti…

The rapid growth in Internet technologies has led to a proliferation in the number of Open Educational Resources (OER), making the evaluation of OER quality a pressing need. In response, a number of rubrics have been developed to help guide the evaluat…

Financial issues regarding the sustainable production, dissemination, and use of Open Educational Resources (OER) in higher education are reviewed and proposed solutions critiqued. Use of OER produce demonstrable cost savings for students. Yet OER deve…

Beginning from two simple assumptions, (i) the speed of light is a universal constant, or its
equivalent, the spacetime intervals are Lorentz invariant, and (ii) there are mutually interacting
particles, with a covariant ‘source-field’ equation, …

For a simple electromagnetic model of a clock introduced by Jefimenko (clock # 1 in 1996 Am. J.
Phys. 64 812), a change of the rate of the clock when it is set in uniform motion is calculated
exactly, employing the correct equation of motion of a cha…

We present a simple setup allowing undergraduate students to reproduce the Hong–Ou–Mandel experiment
during a half-day labwork session and observe the coalescence of two indistinguishable photons
merging on a balanced beamsplitter. This two-photo…

A short introduction is given of direct variational methods and its relation to Galerkin and moment
methods, all flexible and powerful approaches for finding approximate solutions of difficult
physical equations. A pedagogical application of moment m…

This article describes a parallax experiment performed by undergraduate physics students at
Queensland University of Technology. The experiment is analogous to the parallax method used in
astronomy to measure distances to the local stars. The result …

Rolling friction is commonly associated with deformation of the rolling object or surface,
particularly if the object or surface is soft. When a hard object rolls on a hard surface, surface
roughness is also a significant factor. Several experiments …

A promising way to introduce general relativity (GR) in the classroom is to study the physical
implications of certain given metrics, such as the Schwarzschild one. This involves lower
mathematical expenditure than an approach focusing on differentia…

A teaching laboratory experiment is described that uses Archimedes’ principle to precisely
investigate the effect of global warming on the oceans. A large component of sea level rise is due
to the increase in the volume of water due to the decrease…

An analytical solution to the differential equation describing the Duffing oscillator with damping
is presented. The damping term of the differential equation and the initial conditions satisfy an
algebraic equation, and thus the solution is specific…

Two new scenarios are proposed which generalize the standard story leading to the pseudoparadox of
the Einsteinian relativistic twins, thereby enabling some deeper understanding. First, Aesop’s fable
‘The Hare and the Tortoise’ is considered in…

Ego-centric, or first-person, visualization is a valuable tool for an introductory course in general
relativity as well as for public outreach to provide a deeper understanding of the geometric
distortion effects due to curved spacetime. To enhance t…

We point out that in the course of application of Ampère’s law it is important to fulfil the
condition of continuity. We emphasize the role of the displacement current in the case of non-closed
circuits. As a didactical example the magnetostatic f…

In 1978, Landsberg proposed an elegant way of obtaining the inequality between arithmetic and
geometric mean by using the first and second laws of thermodynamics. This result opened a debate on
the logic legitimacy of this procedure to obtain some ma…

A simple method is described to measure the coefficient of rolling friction, ##IMG##
[http://ej.iop.org/images/0143-0807/36/6/065018/ejp519061ieqn3.gif] {${mu }_{{rm{r}}}$} , for a
hard ball rolling on a hard, horizontal surface. The method involve…

Although the electromagnetic field of a given distribution of charge and current is unambiguously
defined by the Maxwell equations, there is no unique inverse correspondence between this field and
point-like sources. We prove this statement for elect…

This paper is devoted to some simple approach based on general physics tools to describe the
physical properties of a hypothetical particle which can be the source of dark energy in the
Universe known as phantom. Phantom is characterized by the fact …

When a person observes an object located at a distance closer than his near point, the object will
appear blurred. Inserting a circular pinhole with a suitable diameter in front of the eye improves
vision. However, vision worsens below a certain pinh…

Through similarities and analogies of Laplace/Poisson equations governing thermal and electric
conduction processes and related phenomena, we show how to indirectly visualize the electric
properties of various configurations, including non-trivial on…

In quantum mechanics, pointer states are eigenstates of the observable of the measurement apparatus
that represent the possible positions of the display pointer of the equipment. The origin of this
concept lies in attempts to fill the blanks in Evere…

The thermal radiation of a black body is investigated using a pyroelectric infrared radiation
detector. This paper presents the construction and operation principles of a simple set-up used for
investigation of black body radiation in a student labor…

The thermal radiation of a black body is investigated using a pyroelectric infrared radiation
detector. This paper presents the construction and operation principles of a simple set-up used for
investigation of black body radiation in a student labor…

In quantum mechanics, pointer states are eigenstates of the observable of the measurement apparatus
that represent the possible positions of the display pointer of the equipment. The origin of this
concept lies in attempts to fill the blanks in Evere…

In quantum mechanics, pointer states are eigenstates of the observable of the measurement apparatus
that represent the possible positions of the display pointer of the equipment. The origin of this
concept lies in attempts to fill the blanks in Evere…

In quantum mechanics, pointer states are eigenstates of the observable of the measurement apparatus
that represent the possible positions of the display pointer of the equipment. The origin of this
concept lies in attempts to fill the blanks in Evere…

This paper analyzes the static equilibrium of a simple jar opener on the basis of rigid-body
mechanics with friction. The opener-lid system is described as a disk lying inside a wedge, where
only one side has friction; the disk is assumed to be acted…

The authors reply to a comment made on a previous paper (Bernardo et al 2015 Eur. J. Phys. 36
[http://dx.doi.org/10.1088/0143-0807/36/2/025016/] 025016 ).

This paper deals with the factors that influence the weight of an object near the Earth’s surface.
They are: (1) the Earth’s gravitational force, (2) the centrifugal force due to the Earth’s diurnal
rotation, and (3) tidal forces due to the gravitati…

We comment on the article ‘Wind-influenced projectile motion’ by Bernardo et al (2015 Eur. J. Phys.
36 [http://dx.doi.org/10.1088/0143-0807/025016] 025016 ) where they examine the trajectory of a
particle that is subjected to gravity and a linear…

The straightforward application of energy and linear momentum conservation to the
absorption/emission of photons by atoms allows us to establish the essential features of laser
cooling of two level atoms at low laser intensities. The lowest attainabl…

The Drude formula of ac (frequency-dependent) electric conductivity has been established as a simple
and practically useful model to understand the electromagnetic response of simple free-electron-like
metals. In most textbooks of solid-state physics…

The thermalization of two blocks with distinct initial temperatures put inside an insulated
recipient is an irreversible process to which the entropic version of the second law of
thermodynamics applies, so the entropy of this system must increase. I…

A common mistake in introductory physics textbooks is the omission of the buoyant force exerted by
the air on an object floating in a liquid. One previous work (Lan 2000 Phys. Teach. 38 [http://
http://dx.doi.org/10.1119/1.880449] 125 ) includes that…

An approximate formula for the energy levels of the bound states of a particle in a finite square
well are obtained, without using the Schrödinger equation. The physics and mathematics involved in
this approach are accessible to a gifted high school…

We present a simple diffraction experiment with m -bonacci gratings as a new interesting
generalization of the Fibonacci ones. Diffraction by these non-conventional structures is proposed
as a motivational strategy to introduce students to basic rese…

A set of classical multi-wire proportional chambers was designed and constructed with the main
purpose of efficient cosmic muon detection. These detectors are relatively simple to construct, and
at the same time are low cost, making them ideal for ed…

We show how the Schr?dinger uncertainty relation for a pair of observables can be deduced using the
Cauchy?Schwarz inequality plus successive applications of the commutation relation involving the two
observables. Our derivation differs from the orig…

We show how the Schrödinger uncertainty relation for a pair of observables can be deduced using the
Cauchy–Schwarz inequality plus successive applications of the commutation relation involving the two
observables. Our derivation differs from the o…

The current use of two sets of units in the UK continues to be a source of muddle and confusion.
Young people are taught metric (SI) units in school but, in the outside world, still have to contend
with units such as inches, feet, pounds, stones and …

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In this paper we consider the main properties of cylindrical lenses and propose several
demonstrational experiments that can be performed with them. Specifically we use simple glasses full
of water to demonstrate some basic geometrical optics princip…

If the end of a long chain, which is contained in an elevated beaker, is dropped over the edge of
the beaker and falls, it is observed that as the speed of the chain increases the chain rises to
form a loop well above the top of the beaker. The name …

Some pre-service teaching activities can contribute much to the learning of pedagogical content
knowledge (PCK) and subsequent teaching as these activities are generating PCK within the
pre-service teacher’s own classroom. Three examples are descri…

This study was done to develop a simple and inexpensive wave driver that can be used in experiments
on string waves. The wave driver was made using a battery-operated toy car, and the apparatus can be
used to produce string waves at a fixed frequency…

According to the Greek historian Herodotus, it took a task force of 100 000 men and 20 years to
build up the Great Pyramid of Gizeh or Khufu’s Pyramid. In this work we discuss an analytical
solution obtained in the framework of basic Newtonian me…

The continuing fascination of young people with celestial bodies leads them to pose challenging
questions to their science teachers, such as how was the universe born? How were the stars formed?
In this paper we present an extremely inexpensive but h…

Despite a number of theories in circuit analysis, little is known about the behaviour of ideal equal
voltage sources in parallel, connected across a resistive load. We neither have any theory that can
predict the voltage source that provides the load…

The speed of sound in a solid is determined by the density and elasticity of the material. Young’s
modulus can therefore be calculated once the density and the speed of sound in the solid are
measured. The density can be measured relatively easily,…