Bounded by the statements of Feynman and Galileo, I describe certain tricks that can be useful for the teaching of physics. In particular, I describe the calculation of the center of mass (centroid) of an arc of circumference and a circular sector. For this purpose, I also use Pappus's theorems. An Appendix is available with Archimedes' method to…

Vertical jump height is a widely used variable in sport science and physical education. This narrative review summarizes various numerical methods used to calculate vertical jump height. In force plate technology, the jump height is most commonly calculated using the flight time (FT) or the takeoff velocity (TOV), which provide only the distance…

This computational exercise gives students an in-depth look at the reactants, transition state, and product of the crystal violet alkaline hydrolysis reaction. The exercise, which is aimed at second semester general chemistry students, involves DFT energy calculations on five structures: crystal violet cation, crystal violet alcohol, and 4-water…

Ion transport, involving the diffusion and migration of ions within the electrolyte, stands as a fundamental concept in electrochemistry and serves as the driving force for electrochemical reactions. Electric double layers are critical in the fields of electrochemical energy storage and chemical conversion, constituting a central focus of…

The relativistic addition of velocities is usually introduced early in the study of Einstein's special theory of relativity. The equations are simple enough, but randomly chosen velocities lead to unwieldy calculations that can dishearten the student. This paper presents tables of velocity components in two dimensions, composed of five or fewer…

The trajectory of a ball in air is affected by aerodynamic drag and lift. In general, the trajectory needs to be calculated numerically since the acceleration varies with time in both the horizontal and vertical directions. If the trajectory remains approximately parabolic, then simple analytical solutions can be found, giving useful insights into…

It is difficult for an instructor to just make up valid numbers for B[subscript x], B[subscript y], B[subscript z], E[subscript x], E[subscript y], and E[subscript z] in the creation of homework problems and test questions calculating the Poynting vector. In this paper, 25 examples are given of the electric and magnetic fields of electromagnetic…

Oxidation number (ON) is taught as an electron-counting concept for redox reactions in chemistry curriculum. The molecular formula method, the Lewis formula method, and the structural formula method have all been used to determine ON. However, the task of assigning ON still poses problems for some teachers and students. This paper explores a new…

A simple experiment is described to compare the descent time between two vertically separated points when an object slides down tracks of varying shape. A surprising result is that the descent time is shortest when it follows a circular track rather than a cycloidal track. Cycloidal tracks are usually predicted to result in the shortest descent…

Traditional physical chemistry conceptions of reaction mechanism are formulated in terms of stationary points of an Arrhenius-style "energy profile" that differs sharply (in purpose and form) from the corresponding Robinson-style "arrow-pushing" mechanistic conceptions of organic chemistry. We show here how these diverse…

Even though many physics teachers take their students on a calculation adventure through circular motion and Newton's universal law of gravity to determine Earth's velocity, most of us leave it at that. We present the final result and say, "Look, Earth is moving around the Sun at about 107,000 km/hr (66,000 mph), yet we can't feel the motion…

The analysis, calculations and graphical charts presented here in this paper are based directly on a recently published paper by the first two of the above-named authors. In the present paper, it is clearly demonstrated that all of the following nine (or eleven including the centripetal acceleration and total mechanical energy) principal physical…

Theoretical and practical foundations of basic electrochemical concepts of heterogeneous charge transfer reactions that underline electrochemical processes are presented for their detailed study by undergraduate and postgraduate students. Several simple methods for calculating key variables, such as the half-wave potential, limiting current, and…

The introduction of Computational Chemistry via "Molecular Modelling and Drug Design" course at undergraduate level has opened wide possibilities for students to expand their knowledge of quantum chemistry, organic reaction mechanisms, protein-ligand interactions, drug design, and probable "in vivo" behavior of drug candidates.…

This review describes a computational chemistry exercise aimed at enhancing the understanding of upper-division undergraduates in organic chemistry and physical chemistry regarding the structures and aromaticities of cyclobutadiene and cyclooctatetraene. This exercise exposes students to chemical problems that require computational methods as a…