Before reading this essay, go to your kitchen and find a bottle of Italian salad dressing. Get one that has been sitting still for a while at a fixed temperature--that is, one in thermal equilibrium. You will find an oil-rich layer at the top of the bottle and a vinegar-rich layer at the bottom (see Fig. 1). But think for a moment before spreading…

Many compounds can be represented well in terms of the two-center-two-electron (2c-2e) bond model. However, it is well-known that this approach has limitations; for example, certain compounds require the use of three-center-two-electron (3c-2e) bonds to provide an adequate description of the bonding. Although a classic example of a compound that…

A popular physics legend holds that scissors can cut paper with a speed faster than light. Here this counter-intuitive myth is investigated theoretically using four simple examples of scissors. For simplicity, all cases will involve a static lower scissors blade that remains horizontal just under the paper. In the first case, the upper blade will…

Attitude is one aspect that needs to be considered both for learning activities or learning objects. This study aims to determine the attitudes and motivations of students in mathematics physics subjects. The sample used was 100 students who had studied the Mathematics Physics course. This study employed quantitative research methods with…

Moments of inertia (MOIs) are usually derived via substantial integration and may intimidate undergraduates without prior backgrounds in calculus. This paper presents an intuitive geometric operation, termed "squashing," that transforms an object into an equivalent one with a reduced dimension, whose MOI is simpler to determine. The…

This paper mainly proposes a simple method to record scattered light rays via photography, presenting a clearer and brighter representation of the optical path. This technique is applied to the double-slit interference experiment and single-slit diffraction experiment typically conducted in general physics courses, and shows the intuitive results…

Within the new world perspective, it is expected that the school, as a formal education space, will be able to provide students with the basic information regarding human knowledge accumulated over the years, and also help them be capable of understanding various scientific and technological issues present today. In the specific case of knowledge…

The ubiquitous bouncy ball, or "superball," is an engaging child's toy that has endured for more than 50 years. But what makes a bouncy ball so uniquely suited to its name? Steel balls, for example, are more highly elastic than are butadiene bouncy balls. Yet it is butadiene balls, and not steel balls, that appear in toy stores and…

In this article we consider a well-known simple, very accessible demonstration of surface tension with a small boat propelled by substances that change the surface tension of water. A simple quantitative evaluation is provided that matches well with experimental data. A modification to the experiment is proposed allowing it to continue for a long…

Ray diagrams are widely used in introductory physics textbooks to illustrate the behavior of ideal systems of lenses or mirrors in geometrical optics. Their virtue lies in their explicit display of multiple ray paths connecting object and image points, which leads naturally to an understanding of how a planar object is transformed into a planar…

High voltage supplies are often used in physics classes for demonstrations and laboratory work. These devices deliver several thousand volts DC, while limiting the current to a safe level, typically under 5 mA. One issue with these power supplies is their expense, which means schools may not have one. Less expensive homemade units have been…

It is well known that when two waves are added they produce beats. These beats are the amplitude modulation of the initial waves and occur periodically at a rate equal to the frequency difference of the two waves. Acoustical beats arise from sound waves of nearly equal frequencies. Optical beats arise from the interference of two light waves of…

The various radiation types that make up the electromagnetic (EM) spectrum are ubiquitous and highly significant in modern society. Detection of visible light by the eye facilitates sight, radio waves and microwaves are used in communication technologies, x-rays are used in medical imaging, and gamma rays are frequently employed in medical…

Work, kinetic energy (KE), and potential energy (PE) are key physics concepts, taught in essentially every introductory physics course along with the physical laws such as the work-kinetic energy theorem and the conservation of mechanical energy, which describe how the values of those quantities change during various processes. Quite appropriately…

Literature in science education positions questions as the launching point for scientific inquiry, and widely used standards, such as the Next Generation Science Standards often state: "Science begins with a question" (NGSS Lead States, 2013). Questions have generally been studied for their role in sparking student inquiry or helping…