Experiments suggesting that a change in eye gaze creates a reflexive attention shift tend to confound motion direction and terminal eye direction. However, motion and the onset of motion are known to capture attention. Current thinking about social cognition in autism suggests that there might be a deficit in responding to social (eye gaze) cues…

Design-based research, and particularly its theoretical status, is a subject of debate in the science education community. In the first part of this paper, a theoretical framework drawn up to develop design-based research will be presented. This framework is mainly based on epistemological analysis of physics modelling, learning and teaching…

As part of the "Car Lab Project," students constructed rubber band cars, raced them, and worked through a number of automotive activities. The students engaged in this project certainly had fun, but they also used high-tech gear such as motion sensors and graphing calculators to gather data on the distance and time cars traveled and to generate…

Both harmonic oscillations and friction are the types of concepts in freshman physics that are readily applicable to the "real world" and as such, most students find these ideas interesting. Damped oscillations are usually presented with resistance proportional to velocity, which has the advantage of a relatively straightforward mathematical…

"The 2006 Winter Meeting of the AAPT Was Over..."and the flight home from Anchorage to Cleveland was just about to end--eight hours in the air, only two complimentary beverages, no meals, a jump across four time zones, a one-year-old baby daughter, and a wife whose motto for the week was, "Why did they choose to have a winter meeting in Alaska?"…

It is well-known that a party balloon can be made to fly erratically across a room, but it can also be used for quantitative measurements of other aspects of aerodynamics. Since a balloon is light and has a large surface area, even relatively weak aerodynamic forces can be readily demonstrated or measured in the classroom. Accurate measurements…

A coin tossed onto a table often ends up rolling in such a way that the center of mass remains approximately stationary. Although this phenomenon has been studied for many years and is well-documented in the literature, it is perhaps not widely appreciated in the physics education community that the motion can be understood without the use of…

A magnet suspended in a uniform magnetic field like that of the Earth can be made to oscillate about the field. The frequency of oscillation depends on the strength (magnetic moment) of the magnet, that of the external field, and the moment of inertia of the magnet. It is easily shown and verified by experiment that a simple but nontrivial…

The homotopy perturbation method is used to solve the nonlinear differential equation that governs the nonlinear oscillations of a simple pendulum, and an approximate expression for its period is obtained. Only one iteration leads to high accuracy of the solutions and the relative error for the approximate period is less than 2% for amplitudes as…

We give a systematic development of the theory of the radiation field of an accelerated charged particle with reference to an inertial reference frame in flat spacetime. Special emphasis is given to the role of the Schott energy and momentum in the energy-momentum balance of the charge and its field. It is shown that the energy of the radiation…

I find that students have difficulty with Hamilton's principle, at least the first time they come into contact with it, and therefore it is worth designing some examples to help students grasp its complex meaning. This paper supplies the simplest example to consolidate the learning of the quoted principle: that of a free particle moving along a…

In the framework of Noether's theorem, a distinction between Lagrangian and dynamical symmetries is made, in order to clarify some aspects neglected by textbooks. An intuitive setting of the concept of invariance of differential equations is presented. The analysis is completed by deriving the symmetry properties in the motion of a charged…

In this paper, two simple non-contact and cost-effective methods to acquire data in the student laboratory are applied to investigate the motion of a torsion pendulum. The first method is based on a Hall sensor, while the second makes use of an optical mouse.

A large body of research has shown that verbal phrases such as "move the pen" are better remembered when they are physically enacted than when the same phrases are studied under standard verbal learning instructions (e.g., Engelkamp & Krumnacker, 1980). More recently, a non-literal enactment effect was discovered in which verbal material that was…

An object that moves is spotted almost effortlessly; it "pops out." When the observer is stationary, a moving object is uniquely identified by retinal motion. This is not so when the observer is also moving; as the eye travels through space all scene objects change position relative to the eye producing a complicated field of retinal motion.…