Stored representations of experiences of forces in actions on objects enter into perceptual interpretations and mental simulations of object motions and interactions. In reply to the comment of Hubbard (2012), I clarify some ambiguities in my account (White, 2012) and correct some poor choices of expression. In addition, I address substantive…

This is a case study of a physics undergraduate who claimed that he "uses physics to understand other subjects." This statement suggested that this student could describe issues concerning the transfer of learning and especially instances of far transfer. Detailed instances of far transfer have been difficult to replicate in lab settings.…

We discuss a brief part of a famous paper on sound and light written by Thomas Young in 1800. We show that the proverbial intuition of this famous polymath leads to the discussion of several important and complex fluid dynamics phenomena regarding the behaviour of streams of air. In particular, we show that Young had already explained the adhesion…

The well-known result for the frequency of a simple spring-mass system may be combined with elementary concepts like speed = wavelength x frequency to obtain wave propagation speeds for an infinite chain of springs and masses (masses "m" held apart at equilibrium distance "a" by springs of stiffness "gamma"). These propagation speeds are dependent…

A recent article in "The Physics Teacher" describes a method for analyzing a systematic error in a Boyle's law laboratory activity. Systematic errors are important to consider in physics labs because they tend to bias the results of measurements. There are numerous laboratory examples and resources that discuss this common source of error.

A ball that is projected forward without spin on a horizontal surface will slide for a short distance before it starts rolling. Sliding friction acts to decrease the translation speed v and it acts to increase the rotation speed [omega]. When v = R[omega], where R is the ball radius, the ball will start rolling and the friction force drops almost…

We give an example of cross coursing in which a subject or approach in one course in undergraduate mathematics is used in a completely different course. This situation crosses falling body modelling in an upper level differential equations course into a modest discrete dynamical systems unit of a first-year mathematics course. (Contains 1 figure.)

Physics is a subject where pupils hold a great number of deeply seated misconceptions. Sound is a prime example, as it requires the visualisation of a form of energy that moves imperceptibly through an invisible medium. This article outlines some of the common misconceptions that pupils hold regarding the nature of sound and how it is transmitted,…

As a physics teacher I like recycling old apparatus and using them for demonstrations in my classes. In physics laboratories in schools, sources of high voltage include induction coils or electronic systems that can be bought from companies that sell lab equipment. But these sources can be very expensive. In this article, I will explain how you…

The concept of "perpetual motion" has a long history. The Indian astronomer and mathematician Bhaskara II (12th century) was the first person to describe a perpetual motion (PM) machine. An example of a 13th-century PM machine is shown in Fig. 1. Although the law of conservation of energy clearly implies the impossibility of PM construction, over…

Physics Education Research is a form of social science research in that it uses human subjects. As physicists we need to be aware of the ethical and legal ramifications of performing this research, taking into account the fundamental differences between working with substances and working with people. For several decades, the federal government…

Understanding energy usage is crucial to understanding modern civilization, as well as many of the challenges it faces. Energy-related issues also offer real-world examples of important physical concepts, and as such have been the focus of several articles in "The Physics Teacher" in the past few decades (e.g., Refs. 1-5, noted further below).…

Floating and sinking might be common phenomena, encountered on a daily basis, but still represent conceptually complex scientific topics. Research has shown that most students have certain experiences and their own "theories" that explain why objects sink or float. Unfortunately, many of these "theories" are either misconceptions or are valid only…

Electromagnetic resonators are often used to detect foreign materials. Here we present a simple experiment for the measurement of liquid level. The resonator, consisting of a coil and a capacitor, is brought to resonance by an external magnetic field source, and the corresponding resonance frequency is determined using Fourier analysis combined…

An equation of state of a system is a relationship that connects the thermodynamic variables of the system such as pressure and temperature. Such equations are well known for classical gases but less so for quantum systems. In this paper we develop a van der Waals equation of state for a dilute boson gas that may be used to explain the occurrence…