Physics Education

Published by IOP Publishing
Online ISSN: 1361-6552
Print ISSN: 0031-9120
Publications
Ball drop apparatus showing ball held in place by rod (top), and lever in position striking stop which makes distinct sound right after ball is released (bottom).
Audacity screen showing sounds of lever striking stop (first peak) and ball striking floor (second peak).
The grey line is the theoretical fall time in the absence of air resistance. The blue line is a best fit line which subtracts the delay between ball drop and the noise of the lever hitting the metal stop on the apparatus.
An acoustic method is presented for analyzing the time of falling motion. A ball is dropped from a measured height. The dropping device makes a distinct sound a well-determined time (roughly 14 milliseconds) after release. The ball subsequently makes a second distinct sound when it hits the surface below. These sounds are captured with a microphone resting on the surface and are readily apparent in the acoustic waveform. At each height (0.25m, 0.50m, 0.75m, and 1.00m), the measured drop time agrees with the drop time predicted by the law of falling bodies with a typical accuracy of 4.3 ms.
 
We use a tablet to determine experimentally the dependencies of the magnetic field (B) on the electrical current and on the axial distance from a coil (z). Our data shows a good precision on the inverse cubic dependence of the magnetic field on the axial distance, $B \propto z^{-3}$. We obtain with good accuracy the value of air permeability $\mu_{air}$. We also observe the same dependence of $B$ on $z$ when considering a magnet instead of a coil. Although our estimates are obtained through simple data fits, we also perform a more sophisticated error analysis, confirming the result for $\mu_{air}$.
 
Teaching Methods Matrix. Student responses to the Teaching Style Inventory described in Section 3 for two classes. The triangles represent Section X (N = 10), the circles represent Section Y (N = 14), and the square represents the instructor (the author of this paper).
The form and function of a collaborative assessment known as a "Buddy Quiz" is presented. The assessment is conducted in three successive phases over a contiguous 45- to 60-minute class period. A portion of each Quiz is completed in collaboration with one or two peers and a portion is completed without collaboration. The Quiz is primarily summative and is also designed to include formative aspects. The representation in the Quiz of the scientific enterprise as collaborative and individualistic is discussed. The employment of this instrument in a ninth-grade (age 15 years) conceptual physics course in an independent US secondary school is described and student feedback is presented.
 
The percentage of correct answers for the list of true/false statements, for the public sample.
Similar as Table 1, but for the student sample.
repartition of the main identification criteria for the public sample, and agreement with actual classification data. The sum of the percentages should be 100% but, for the observed values, the total may be less than 100% because some people do not know or do not wish to answer.
This article presents the results of the first survey conducted in Belgium about the interest and knowledge in astronomy. Two samples were studied, the public at large (667 questionnaires) and students (2589 questionnaires), but the results are generally similar in both samples. We evaluated people's interest, main information source, and attitudes towards astronomy, as well as their supposed and actual knowledge of the subject. The main conclusion is that, despite a poor self-confidence, people do know the basic astronomical concepts. However, that knowledge is not deeply rooted, as reasoning questions show well-spread misconceptions and/or misunderstandings.
 
This paper discusses an instructional strategy which explores eventual similarities and/or analogies between familiar problems and more sophisticated systems. In this context, the Atwood's machine problem is used to introduce students to more complex problems involving ropes and chains. The methodology proposed helps students to develop the ability needed to apply relevant concepts in situations not previously encountered. The pedagogical advantages are relevant for both secondary and high school students, showing that, through adequate examples, the question of the validity of Newton's second law may be introduced to even beginning students.
 
This article presents the customization of EJS models, used together with actual laboratory instruments, to create an active experiential learning of measurements. The laboratory instruments are the vernier caliper and the micrometer. Three computer model design ideas that complement real equipment are discussed in this article. They are 1) the simple view and associated learning to pen and paper question and the real world, 2) hints, answers, different options of scales and inclusion of zero error and 3) assessment for learning feedback. The initial positive feedback from Singaporean students and educators points to the possibility of these tools being successfully shared and implemented in learning communities, and validated. Educators are encouraged to change the source codes of these computer models to suit their own purposes, licensed creative commons attribution for the benefit of all humankind. Video abstract: http://youtu.be/jHoA5M-_1R4
 
Receding photon front as seen by a farmer in the barn 
We present two different paradoxes related to the length contraction in special relativity and explain their resolution.
 
An elephant femur helps illustrate the biophysics of bone shape, and attracts attention while being carted through campus. 
Improving the scientific literacy of non-scientists is an important goal, both because of the ever-increasing impact of science and technology on our lives, and because understanding science enriches our experience of the natural world. One route to improving scientific literacy is via general education undergraduate courses -- i.e. courses intended for students not majoring in the sciences or engineering -- which in many cases provide these students' last formal exposure to science. I describe here a course on biophysics for non-science-major undergraduates recently developed at the University of Oregon (Eugene, OR, USA). Biophysics, I claim, is a particularly useful vehicle for addressing scientific literacy. It involves important and general scientific concepts, demonstrates connections between basic science and tangible, familiar phenomena related to health and disease, and illustrates that scientific insights develop by applying tools and perspectives from disparate fields in creative ways. In addition, biophysics highlights the far-reaching impact of physics research. I describe the general design of this course, which spans both macroscopic and microscopic topics, and the specific content of a few of its modules. I also describe evidence-based pedagogical approaches adopted in teaching the course, and aspects of its enrollment and evaluation.
 
Experimental setup showing top and bottom views of glass tubes with flowing bitumen. The radius of orifices increases from left to right.  
Slow flow of the viscous liquid is a thought-provoking experiment that challenges students, academics and public to think about some fundamental questions in modern science. In the Queensland demonstration, the world-longest running experiment earning the Ig Nobel prize, one drop of pitch takes about 10 years to fall, leading to problems of actually observing the drops. Here, we describe our recent demonstration of slowly-flowing bitumen where appreciable flow is observed on the time scale of months. The experiment is free from dissipative heating effects and has the potential to improve the accuracy of measurement. Bitumen viscosity was calculated by undergraduate students during the summer project. The worldwide access to the running experiment is provided by webcams uploading the images to a dedicated website, enhancing student education experience and promotion of science. This demonstration serves as an attractive student education exercise and stimulates the discussion of fundamental concepts and hotly debated ideas in modern physics research: difference between solids and liquids, the nature of liquid-glass transition, emergence of long time scales in a physical process, and the conflict between human intuition and physical reality.
 
In this paper we propose strategies and methodologies of teaching topics in high school physics, through a show of Educational Robotics. The Exhibition was part of a set of actions promoted by a brazilian government program of incentive for teaching activities (PIBID) and whose primary focus is the training of teachers, improvement of teaching in public schools, dissemination of science and formation of new scientists and researchers. By means of workshops, banners and prototyping of robotics, we are able to create a connection between the study areas and their surrounding, making learning meaningful and accessible for the students involved and contributing to their cognitive development.
 
Lessons and homework problems involving a pendulum are often a big part of introductory physics classes and laboratory courses from high school to undergraduate levels. Although laboratory equipment for pendulum experiments is commercially available, it is often expensive and may not be affordable for teachers on fixed budgets, particularly in developing countries. We present a low-cost, easy-to-build rotary sensor pendulum using the existing hardware in a ball-type computer mouse. We demonstrate how this apparatus may be used to measure both the frequency and coefficient of damping of a simple physical pendulum. This easily constructed laboratory equipment makes it possible for all students to have hands-on experience with one of the most important simple physical systems.
 
A Faraday cage is an interesting physics phenomena where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can! The background of the physics behind this is described in some detail followed by a explanation of some demonstrations and experiments which I have used.
 
Schematic drawing of the experimental setup: 1 power supply, 2 digital camera, 3 a bowl containing water, 4 stirring motor, 5 black rubber floor, 6 three candy samples. 
A series of pictures taken throughout a certain measurement. (a) calibration with a 50 Euro cent coin; The dissolution of the candies after (b) 0, (c) 1, (d) 7, (e) 10 and (f) 15 minutes. The stripes are coming from the rubber background. The candies change their position slightly in time due to the flow provided by the stirring motor. 
The result of the measurement depicted in Figure 4. The three candies dissolve more or less linearly in time, as proposed by our simple model. Below 2 mm in diameter, the behavior of the dissolution changes drastically. These points have been excluded from the fit-area. 
Assuming a constant mass-decrease per unit-surface and -time we provide a very simplistic model for the dissolution process of spherical candies. The aim is to investigate the quantitative behavior of the dissolution process throughout the act of eating the candy. In our model we do not take any microscopic mechanism of the dissolution process into account, but rather provide an estimate which is based on easy-to-follow calculations. Having obtained a description based on this calculation, we confirm the assumed behavior by providing experimental data of the dissolution process. Besides a deviation from our prediction caused by the production process of the candies below a diameter of 2 mm, we find good agreement with our model-based expectations. Serious questions on the optimal strategy of enjoying a candy will be addressed, like whether it is wise to split the candy by breaking it with the teeth or not.
 
EJS applet view of the virtual laboratory simulation learning environment showing a world view and a bottom control panel for student- directed inquiry activities . 
Table of data showing individual and total momentum and kinetic energies before and after collision for ease of retrieving information for data
Scientific graphical plots of momentum (left) notice, the (total momentum) red line is constant at-4.0 kg.m/s and kinetic energies (right) (total kinetic energies) purple line reflect a drop in kinetic energies at time of collision. There are selectable check-boxes for individual cart and total for multiple representations and further data analyis.
We develop an Easy Java Simulation (EJS) model for students to experience the physics of idealized one-dimensional collision carts. The physics model is described and simulated by both continuous dynamics and discrete transition during collision. In the field of designing computer simulations, we discuss briefly three pedagogical considerations such as 1) consistent simulation world view with pen paper representation, 2) data table, scientific graphs and symbolic mathematical representations for ease of data collection and multiple representational visualizations and 3) game for simple concept testing that can further support learning. We also suggest using physical world setup to be augmented complimentarily with simulation while highlighting three advantages of real collision carts equipment like tacit 3D experience, random errors in measurement and conceptual significance of conservation of momentum applied to just before and after collision. General feedback from the students has been relatively positive, and we hope teachers will find the simulation useful in their own classes.
 
Two serially wired TEPT4400 phototransistors connected to the 3,5mm jack plug. Clothes-pegs can help to set the distance between the detectors easily and quickly. 
Free fall experiment demonstrates the high resolution and precision of the stopwatch. An Excel spreadsheet fragment shows the five measured values with mean ( μ =0.0599 s) and standard deviation ( σ =0.00024 s). 
A very low-cost, easy-to-make stopwatch is presented to support various experiments in mechanics. The high-resolution stopwatch is based on two photodetectors connected directly to the microphone input of the sound card. A dedicated free open-source software has been developed and made available to download. The efficiency is demonstrated by a free fall experiment.
 
We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from a commonly used chamber is use of a heat sink as its bottom plate. A result of a performance test of the chamber is given.
 
Left: A US commemorative postage stamp which was issued at the University of Chicago on Sept. 29, 2001, portrays Enrico Fermi. Right: First atomic bomb test, near Alamogordo, New Mexico, July 16, 1945. Picture is from U.S. Department of Energy, Los Alamos National Laboratory, New Mexico.
Left: exterior view of the space station. Right: interior view of space station.
A team of people walks on the surface of Mars as it would walk on Earth. Still is taken from Red Planet [18].
During the past several years the authors have developed a new approach to the teaching of Physical Science, a general education course typically found in the curricula of nearly every college and university. This approach, called `Physics in Films', uses scenes from popular movies to illustrate physical principles and has excited student interest and improved student performance. The analyses of many of the scenes in `Physics in Films' are a direct application of Fermi calculations -- estimates and approximations designed to make solutions of complex and seemingly intractable problems understandable to the student non-specialist. The intent of this paper is to provide instructors with examples they can use to develop skill in recognizing Fermi problems and making Fermi calculations in their own courses.
 
A project known as "Physics in Films" currently underway at UCF is designed to generate renewed interest and excitement in the standard "Physical Science" course. In the initial, developmental phase of the project the instructors selected films without regard to genre and theme. They only demanded that the selected films would cover nearly all the traditional topics of the typical "Physical Science" course. The project met with unprecedented success that motivated a rapid and more sophisticated expansion. In the current phase the authors demonstrate that the method is very flexible, accommodating the movie preferences of any instructor. The authors are developing versions of the course that have different "flavors", that is, "Physics in Films" course packages built around particular genres or themes. For example, during the 2003 summer terms we class-tested the flavors "Physics in Films: Superheroes" and "Physics in Films: Pseudoscience". Additional flavors are under development. This talk summarizes part of our experiences and presents some of the results from our courses. Overall, the method opens an effective way to help large masses to overcome science illiteracy.
 
(Color online)-Oscillator with a variable mass. A bucket filled with water is attached to a spring. The water flows out through a small hole in the bottom of the bucket. 
(Color online)-Screen shot of the spreadsheet implementation of the numerical procedure described in Section 4 and detailed above. The columns contain the sequences t i , z i , v i , a i , m w (t i ) and the z − z 0 , with z 0 given by equation (10). Subsequent values of z i+1 and v i+1 are computed from cell entries in rows (i − 1). The plot depicts the obtained results for z(t) − z 0. The starting values of z, v, and m w are 0 m, 0 m·s −1 and 10 kg, respectively. The used values of the other parameters are g = 9.8 m·s −2 , k = 100.0 kg·s −1 , m b = 1.0 kg (mass of the bucket), and h = 0.05 s (the time step). 
This work is basically about the general form of Newton's second law for variable mass problems. We develop a model for describing the motion of the one-dimensional oscillator with a variable mass within the framework of classroom physics. We present a simple numerical procedure for the solution of the equation of motion of the system to be implemented by students and teachers. Interesting qualitative concepts as well as quantitative results for the focused problem are presented. The topic has pedagogical value both from theoretical and experimental point of view. However, this article considers only theoretical aspects of the problem. The work is addressed to basic physics courses at undergraduate level.
 
The transit of a planet (passing from A to B) around a star. The observer is located off the right-hand side of the paper. In this model we assume a circular orbit for the planet. 
The field of extrasolar planets is still, in comparison with other astrophysical topics, in its infancy. There have been about 300 or so extrasolar planets detected and their detection has been accomplished by various different techniques. Here we present a simple laboratory experiment to show how planets are detected using the transit technique. Following the simple analysis procedure describe we are able to determine the planetary radius to be 1.27 +/- 0.20 R_{J} which, within errors agrees with the establish value of 1.32 +/- 0.25 R_{J}.
 
A two dimensional Cartesian coordinate system using a tiled floor in the SWS game. 
Visualization of paths (green curve) in three-dimensional space in the SWS game. The arrow points along the instantaneous direction of travel. 
The spear in the Glight game as a representation of the velocity vector. As the player moves the character along the circle, the spear must be simultaneously controlled to remain along the tangent.
The right panel shows the effect of placing bombs on one side of a sphere in the Glight game. The same two bombs placed on opposite sides lead to a different trajectory as seen in the left panel. The trajectories are indicated schematically by the green arrows.
Experimenting with rigid body motion in the UnC2 game. The translational and rotational motion of a flask depends on where it is shot. This is controlled by the player using the on-screen reticle (white circle near the top of the red flask). 
Commercial video games are increasingly using sophisticated physics simulations to create a more immersive experience for players. This also makes them a powerful tool for engaging students in learning physics. We provide some examples to show how commercial off-the-shelf games can be used to teach specific topics in introductory undergraduate physics. The examples are selected from a course taught predominantly through the medium of commercial video games.
 
Positions of the focal point and centre of curvature of a spherical concave mirror. Rays 1 and 2, and their respective reflections 1 ′ and 2 ′ in the mirror, determine the location of the image.
Schematics of the spherical concave mirror experiment for measuring the refractive index of water. The support holding the lamp is moved up and down until a sharp image of the lamp is formed on the screen.  
Formation of the images at the positions of the actual and apparent centres of curvature.
Schematic of the silvered lens analogue.
This paper describes the spherical concave mirror method for measuring the index of refraction of transparent liquids. We derived the refractive index equation using Snell's law and the small-angle approximation. We also verified the validity of this method using the traditional spherical mirror and thin-lens Gaussian equations.
 
The telescope counting ratio (solid line and left scale) and atmospheric pressure (dashed line and right scale) registered in January 2006.
Scattered plot telescope counting rate vs. atmospheric pressure registered in January 2005. Each point represents one hour counting results.
A group of high school students (XII Liceum) in the framework of the Roland Maze Project has built a compact telescope of three Geiger-Muller counters. The connection between the telescope and PC computer was also created and programed by students involved in the Project. This has allowed students to use their equipment to perform serious scientific measurements concerning the single cosmic ray muon flux at ground level and below. These measurements were then analyzed with the programs based on the 'nowadays' knowledge on statistics. An overview of the apparatus, methods and results were presented at several students conferences and recently won the first prize in a national competition of high school students scientific work. The telescope itself, in spite of its 'scientific' purposes, is built in such a way that it is hung on a wall in a school physics lab and counts muons continuously. This can help to raise the interest for studying physics among others. At present a few (3) groups of young participants of the Roland Maze Project have already built their own telescopes for their schools and some others are working on it. This work is a perfect example of what can be done by young people when respective opportunities are created by more experienced researchers and a little help and advice is given.
 
Since October 2010, the Chemistry-Biology Combined Major Program (CBCMP), an international course taught in English at Osaka University, has been teaching small classes (no more than 20 in size). We present data from the Force Concept Inventory (FCI) given to first year classical mechanics students ($N=47$ students over three years) pre and post score, for a class that predominantly uses interactive engagement (IE), such as MasteringPhysics. We also comment on possible correlations between the pre/post score and the level of English ability on entry to the course; importantly, there does appear to be a correlation with reading ability, which is not typically a criteria for entrance to Japanese global courses (usually only a total TOEFL $\sim 80$ is required). Our findings show a $G$-factor improved score of about $\sim 0.18$, which is marginally about the average of a traditional based course. Given that the number of test subjects are quite small, we analyze in detail a set of six questions from the FCI, involving the identification of forces acting on a body. We find that student answers tend to cluster about "polarizing choices"---a pair of choices containing the correct choice and a wrong choice with the latter corresponding to a super-set of forces in the former. Our results are suggestive that students have a good idea of the right set of forces acting on a given system but this set contains extra force(s) that is (are) ontologically miscategorized.
 
The diagram for the interference quiz.
The single narrow slit simulation. 
Studies have shown that standard lectures and instructional laboratory experiments are not effective at teaching interference and diffraction. In response, the author created an interactive computer program that simulates interference and diffraction effects using the Finite Difference Time Domain method. The software allows students to easily control, visualize, and quantitatively measure the effects. Students collected data from simulations as part of their laboratory exercise, and they performed well on a subsequent quiz---showing promise for this approach.
 
The magnets attracting each other. The dipol directions shown by arrows.
The magic angle in the simplest configuration
Many students meet quite early this dipole-dipole potential energy when they are taught electrostatics or magnetostatics, and it is also a very popular formula, featured in the encyclopedias. We show that by a simple rewriting of the formula it becomes apparent that for example, by reorienting the two dipoles, their attraction can become exactly twice as large. The physical facts are naturally known, but the presented transformation seems to underline the geometrical features in a rather unexpected way. The consequence of the discussed features is the so called magic angle which appears in many applications. The present discussion also contributes to an easier introduction of this feature. We also discuss a possibility for designing educational toys and try to suggest why this formula has not been written down frequently before this work. Similar transformation is possible for the field of a single dipole, there it seems to be observed earlier, but also in this case we could not find any published detailed discussion.
 
Boat wakes on the Vltava river, Prague. 
Kelvin wave fronts on deep water. Dashed lines indicate the ship's path and the boundary of the Kelvin wedge. Evanescent waves extending beyond the wedge are shown as dotted lines.
Section of a wave front in the wake of a ship, shown at two different times separated by interval t. The ship moves from right to left with velocity v. The (phase) velocity of the wave is c and the angle between the wave front and the ship's path is θ.
Google Earth picture of a ferry boat near Rio de Janeiro. Measurements performed on the image give λ = 22 m and θ = 43 • . The 50 m scale is fixed by Google Earth. The calculated boat speed is v = 31 km/h.
Google Earth photographs often show ships and their wakes in great detail. We discuss how the images can be used to calculate the velocity of these ships.
 
Orbital view of Earth as a 3D sphere and the universe in the background of the 3D drawing panel in EJS implemented in Java 3D. 
Orbital view of Earth non-geostationary cirular orbit of R = 3*REarth with a period of 7.3 hours, in the equator plane and same rotation sense as Earth.
A free body diagram of Earth and satelite showing the forces (teal) on the Earth and satellite as equal and opposite in direction acting on different bodies. 
We develop an Easy Java Simulation (EJS) model for students to visualize geostationary orbits near Earth, modeled using Java 3D implementation of the EJS 3D library. The simplified physics model is described and simulated using simple constant angular velocity equation. Four computer model design ideas such as 1) simple and realistic 3D view and associated learning to real world, 2) comparative visualization of permanent geostationary satellite 3) examples of non-geostationary orbits of different 3-1) rotation sense, 3-2) periods, 3-3) planes and 4) incorrect physics model for conceptual discourse are discussed. General feedback from the students has been relatively positive, and we hope teachers will find the computer model useful in their own classes.
 
We discuss the flat and hollow models of the Earth as a pedagogical example of the application of Gauss' law to the gravitational field.
 
Examples of wave refraction, the wave fronts bend approaching the beach a) Villaricos, Spain, 4/26/2002, coordinates: 37 0 14 ′ 04 . 59” N , 1 0 47 ′ 04 . 79” E . b) Sardegna, Italy, 8/18/2010, coordinates: 
Google Earth is a huge source of interesting illustrations of various natural phenomena. It can represent a valuable tool for science education, not only for teaching geography and geology, but also physics. Here we suggest that Google Earth can be used for introducing in an attractive way the physics of waves.
 
This paper reports a computer model- simulation created using Easy Java Simulation (EJS) for learners to visualize how the steady-state amplitude of a driven oscillating system varies with the frequency of the periodic driving force. The simulation shows (N=100) identical spring-mass systems being subjected to (1) periodic driving force of equal amplitude but different driving frequencies and (2) different amount of damping. The simulation aims to create a visually intuitive way of understanding how the series of amplitude versus driving frequency graphs are obtained by showing how the displacement of the system changes over time as it transits from the transient to the steady state. A suggested how to use the model is added to help educators and students in their teaching and learning, where we explained the theoretical steady state equation, time conditions when the model starts allowing data recording of maximum amplitudes to closely match the theoretical equation and steps to collect different runs of degree of damping. We also discuss two design features in our computer model: A) displaying the instantaneous oscillation together with the achieved steady state amplitudes and B) explicit world view overlay with scientific representation with different degrees of damping runs. Three advantages of using EJS include 1) Open Source Codes and Creative Commons Attribution Licenses for scaling up of interactively engaging educational practices 2) models made can run on almost any device including Android and iOS and 3) allows for redefining physics educational practices through computer modeling.
 
Picture taken with a modified webcam.
Photovoltaic cell slectroluminescence taken with a cheap set-up
Here we propose two methods to get electroluminescence images from photovoltaic cells in a school or home lab.
 
A key question in physics education is the effectiveness of the teaching methods. A curriculum that has been investigated at the University of Central Florida (UCF) over a period of two years is the use of particular elements of The Physics Suite. Select sections of the introductory physics classes at UCF have made use of Interactive Lecture Demonstrations as part of the lecture component of the class. The lab component of the class has implemented the RealTime Physics curriculum, again in select sections. The remaining sections have continued with the teaching methods traditionally used. Using pre- and post-semester concept inventory tests, a student survey, student interviews, and a standard for successful completion of the course, the data indicates improved student learning.
 
The discovery of quantum mechanics at the beginning of the last century led to a revolution of the physical world view. Modern experiments, made possible by new techniques on the border of the classical and the quantum regimes offer new insights and better understanding of the quantum world and have impact on technical development. Therefore it seems important that students gain appreciation of the principles of quantum mechanics. A suitable way seems be the treatment of the EPR-experiment at a prominent place.
 
The model of the Big Bang is an integral part of the national curriculum for England. Previous work (e.g. Baxter 1989) has shown that pupils often come into education with many and varied prior misconceptions emanating from both internal and external sources. Whilst virtually all of these misconceptions can be remedied, there will remain (by its very nature) the obstacle of ex-nihilo, as characterised by the question `how do you get something from nothing?' There are two origins of this obstacle: conceptual (i.e. knowledge-based) and cultural (e.g. deeply held religious viewpoints). The article shows how the citizenship section of the national curriculum, coming `online' in England from September 2002, presents a new opportunity for exploiting these. Comment: 6 pages. Accepted for publication in Physics Ed
 
The interconnections among the different representations that describe the phenomenon.
(a) Students’ depiction of the motion of the ball with the graphical representation. (b) The graphs depicting the equations of motion for this specific situation. 
A screen capture of the simulation program showing the diagrammatic and graphical
representations of the ball's motion in terms of the total energy, kinetic energy and
potential energy.
Comparison of graphs for the bounce of a ball with and without air resistance.
We describe an example of learning with multiple representations in an A-level revision lesson on mechanics. The context of the problem involved the motion of a ball thrown vertically upwards in air and studying how the associated physical quantities changed during its flight. Different groups of students were assigned to look at the ball's motion using various representations: motion diagrams, vector diagrams, free-body diagrams, verbal description, equations and graphs, drawn against time as well as against displacement. Overall, feedback from students about the lesson was positive. We further discuss the benefits of using computer simulation to support and extend student learning.
 
In Tracker view with world view( LEFT) and the 3 plots (RIGHT) with y versus t,vy versus t and ay versus t showing the real world data (RED) and the a higher initial velocity on Earth's surface model A(TEAL) allows for comparative analysis.
In Tracker view with world view( LEFT) and the 3 plots (RIGHT) with y versus t,vy versus t and ay versus t showing the real world data (RED) and the Moon model A(TEAL) allows for comparative analysis.
This paper reports the use of Tracker as a pedagogical tool in supporting effective learning and teaching of toss up and free fall motion for beginning grade 9 students. This is a case study with (N=123) students of express-pure physics classes in a mainstream school in Singapore where we used a 8 multi-choice questions as a proxy to assess learning gains in pre and posttest to gauge the impact on learning. We found within experimental group gains with Cohens effect size d = 0.79 error 0.23 (large effect) and normalized gains with a gradient of g total = 0.42 error 0.08 (medium gain) above the traditional baseline value of g non interactive=0.23 for all the 6 teachers, 3 classes of students who participated in this study. Initial research findings suggest that allowing learners to relate abstract physics concepts to real life through coupling traditional video analysis and eventually video modeling could be an innovative and effective way to learn free fall motion. Finally, we discuss the pedagogical use of Tracker to extend the learning of free fall by means of allowing students to construct simple dynamic particle models for scenarios that are difficult to visualize their velocity versus time graphs such as 2 cases compare to tossing up a ball with a) with a greater force on Earth and b) with the same force on Moons surface.
 
A closer look (with hindsight) at Newtonian and relativistic kinematics reveals two things. Not surprisingly, Newtonian time remains the empty and artificial - albeit useful - figment it is known to be. Quite unexpectedly however it turns out that with an only slightly more physical time-concept, time and space remain separate entities and simultaneity of events becomes a meaningful concept even for physicists.
 
In this paper we describe an alternative use of the loop-the-loop apparatus, which can be used to study an interesting case of projectile motion. We also present an effective way to perform and analyze these experiments, by using video capture software together with a digital video camera. These experiments can be integrated into classroom demonstrations for general physics courses, or become part of laboratory activities.
 
In classical mechanics matter and fields are completely separated. Matter interacts with fields. For particle physicists this is not the case. Both matter and fields are represented by particles. Fundamental interactions are mediated by particles exchanged between matter particles. In this paper we explain why particle physicists believe in such a picture, introducing the technique of Feynman diagrams starting from very basic and popular analogies with classical mechanics, making the physics of elementary particles comprehensible even to high school students, the only prerequisite being the knowledge of the conservation of mechanical energy.
 
I discuss some interesting classroom demonstrations of diamagnetism and how this effect can produce levitation. The possibilities for hands-on demonstrations of diamagnetic and superconducting levitation are discussed. To conclude I discuss some practical uses for levitation in daily life.
 
Setup of the Logistic Map device. An array of ten LEDs are connected to the Arduino microcontroller using the same number of 220 Ω resistors. 
Circuit diagram of the ten LEDs array connected to the Arduino. 
Cobweb diagrams for the logistic map for different values of A and X 0 . The 45 ◦ line, 
The logistic map is one of the simplest nonlinear dynamical systems that clearly exhibit the route to chaos. In this paper, we explored the evolution of the logistic map using an open-source microcontroller connected to an array of light emitting diodes (LEDs). We divided the one-dimensional interval $[0,1]$ into ten equal parts, and associated and LED to each segment. Every time an iteration took place a corresponding LED turned on indicating the value returned by the logistic map. By changing some initial conditions of the system, we observed the transition from order to chaos exhibited by the map.
 
A set of examples is provided that illustrate the use of work as applied to simple machines. The ramp, pulley, lever and hydraulic press are common experiences in the life of a student and their theoretical analysis therefore makes the abstract concept of work more real. The mechanical advantage of each of these systems is also discussed so that students can evaluate their usefulness as machines. Comment: 9 pages, 4 figures
 
This paper reports the use of Tracker as a pedagogical tool in the effective learning and teaching of projectile motion in physics. When computer model building learning processes is supported and driven by video analysis data, this free Open Source Physics (OSP) tool can provide opportunities for students to engage in active inquiry-based learning. We discuss the pedagogical use of Tracker to address some common misconceptions of projectile motion by allowing students to test their hypothesis by juxtaposing their mental models against the analysis of real life videos. Initial research findings suggest that allowing learners to relate abstract physics concepts to real life through coupling computer modeling with traditional video analysis could be an innovative and effective way to learn projectile motion.
 
Comparing the performance of the students of 1 st , 2 nd and 3 rd year in an exam as a function of their class's mean reaction time. The line is only to show trend.
The reaction time of a group of students majoring in Physics is reported here. Strong co-relation between fatigue, reaction time and performance have been seen and may be useful for academicians and administrators responsible of working out time-tables, course structures, students counsellings etc. Comment: 10 pages, 4 figures
 
(a) shows the two possible configurations of transformers used in 3phase supply. (b) and (c) shows examples of how load can be connected to the star transformer.
The two Phases (A and C) as seen by the dual trace picoscope 2202. Also, shown is the generated 3-phase supply using sinusodial wave from function generator (Phase A) and Phase B and Phase C using phase shift circuits. 
A half-wave rectification circuit for three phase supply. The output waveform of this circuit shows that the ripples would be less than the case of half-wave rectification of a single phase supply. 
The power distribution of nearly all major countries have accepted 3-phase distribution as a standard. With increasing power requirements of instrumentation today even a small physics laboratory requires 3-phase supply. While physics students are given an introduction of this in passing, no experiment work is done with 3-phase supply due to the sheer possibility of accidents while working with such large powers. We believe a conceptual understanding of 3-phase supply would be useful for physics students with hands on experience using a simple circuit that can be assembled even in a high school laboratorys.
 
Experimental setup to determine the spring constants of springs in series. A soft spring of mass m s = 4 . 43 ± 0 . 01 g, radius r = 1 . 0 ± 0 . 1 cm, and n = 36 turns, is 
Figure captions
Springs are used for a wide range of applications in physics and engineering. Possibly, one of its most common uses is to study the nature of restoring forces in oscillatory systems. While experiments that verify the Hooke's law using springs are abundant in the physics literature, those that explore the combination of several springs together are very rare. In this paper, an experiment designed to study the static properties of a combination of springs in series using only one single spring is presented. Paint marks placed on the coils of the spring allowed us to divide it into segments, and considered it as a collection of springs connected in series. The validity of Hooke's law for the system and the relationship between the spring constant of the segments with the spring constant of the entire spring is verified experimentally. The easy setup, accurate results, and educational benefits make this experiment attractive and useful for high school and first-year college students.
 
Zulfi Erken teaches physics in English at a Russian town between the Volga and the Urals. Here he reveals how his students can overcome difficulties such as insufficient equipment to learn physics in a foreign language and go on to study at universities abroad.
 
The author describes the discovery of the electron, electrons in atoms, properties of free electrons, theories of electrons, sources and finally applications of electrons in industry and medicine.
 
The Standard Model is the generally accepted model of the fundamental particles of matter. It allows six quarks, six leptons and various `field quanta' which account for the interactions between particles. This article describes the model and makes some suggestions for improvement.
 
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D. M. Watts
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