An atlatl or spearthrower is perhaps humanity's oldest technology for accelerating projectiles. The dynamics prior to launch of the dart projectile have been much discussed in the literature. In this article we present a simple new model of launch dynamics and show that dart flex is not an important factor in determining launch speed, but it…

Simple energy balance models of planetary systems are of fundamental importance to understanding equilibrium temperatures. Most textbooks that discuss energy balance take a further step and include the effects of an atmosphere on the surface temperature. It is noticeable, however, that in such discussions of planetary surface energy balance some…

Teaching and learning introductory thermodynamics has drawn considerable research attention over the last two decades, especially in several disciplines of higher education. Under particular investigation is the First Law of Thermodynamics (FLT), which offers an expression of energy conservation in thermodynamic systems, as the evidence shows that…

Kinetic energy is usually the entry point for the study of energy in physics and is often perceived as unproblematic. We present evidence, however, that some learners who seem to have accepted the concept, from elementary school students to college physics majors and in-service teachers, nevertheless do not consistently attribute kinetic energy to…

The Next Generation Science Standards lay out a model of energy that locates energy within objects and fields, and tracks energy as it transfers between these objects and transforms between forms of energy while always being conserved. This model of energy pervades much of modern science and represents a foundational, cross-cutting concept for…

The Gaussian gun is an arrangement of magnets and ball bearings (pictured in Fig. 1) such that--when the leftmost ball is released--the rightmost ball is ejected at high speeds. The device has been described in several articles on energy education. The sudden appearance of kinetic energy offers a productive context for considering a range of…

The challenge of accurately assessing critical thinking in physics education, particularly on topics like work and energy, remains a key issue for educators. The current study aims to address this challenge by exploring students' critical thinking abilities using two-tier test data analyzed through the Rasch model. Data were collected from…

Identifying and understanding student difficulties with physics content in a wide variety of topical areas is an active research area within the physics education research community. Of particular value are investigations of physics topics that appear multiple times in different contexts across the undergraduate physics curriculum. As these common…

This work is the fourth of a series of papers applying multidimensional item response theory (MIRT) to widely used physics conceptual assessments. This study applies MIRT analysis using both exploratory and confirmatory methods to the Brief Electricity and Magnetism Assessment (BEMA) to explore the assessment's structure and to determine a…

An application for visualizing the dynamic properties of an equimolar binary mixture of isotropic reactive particles is presented. By introducing a user selectable choice for the activation energy, the application is useful to demonstrate qualitatively that the reaction rate depends on the above choice and on temperature. The application is based…

We present a simple activity based on the liquid-drop model which allows secondary school students to explore the uses of mathematical models and gain an intuitive understanding of the concept of binding energy, and in particular the significance of positive binding energy. Using spreadsheets provided as supplementary material, students can…

For proper assessment selection understanding the statistical similarities amongst assessments that measure the same, or very similar, topics is imperative. This study seeks to extend the comparative analysis between the brief electricity and magnetism assessment (BEMA) and the conceptual survey of electricity and magnetism (CSEM) presented by…

Teaching simple circuits and Ohm's law to students in the introductory classroom has been extensively investigated through the common practice of using incandescent light bulbs to help students develop a conceptual foundation before moving on to quantitative analysis. However, the bulb filaments' resistance has a large temperature dependence,…

This study sought to examine the impacts of the application of the McCarthy Model (4MAT) teaching approach in enhancing seventh-grade female students' conceptions of electricity in physics. The study sample comprised a total of 41 female students, who were selected from two schools located in the Kingdom of Saudi Arabia's city of Aljouf. The…

This action research study used data from multiple assessments in Mechanics and Electricity and Magnetism to determine the viability of Modeling Instruction as a pedagogy for students in AP Physics C: Mechanics and Electricity and Magnetism. Modeling Instruction is a guided-inquiry approach to teaching science in which students progress through…