In this work we describe a simple setup for measuring electrostatic charge and polarity in electrostatic experiments. This low-cost detector only requires a graphite pencil, a capacitor, two switches, and a voltmeter, and holds the promise of transforming qualitative activities that are commonly used to teach electrostatics into quantitative…

Measuring magnetic induction is occasionally performed by our students during their academic training in physics. Among the various methods used to measure it, the Hall effect is the most common and widespread. Another way consists of employing an electronic flux-meter. It is constituted by a small flat coil (SFC) connected to the input of an…

A planetarium is an invaluable tool for teaching introductory astronomy, but one that few astronomy educators have ready access to. Here we describe a do-it-yourself planetarium that can be built with modest funding. There have been other planetarium construction projects described in the literature and online, most of which use cardboard to make…

Magnets are familiar objects and yet magnetism as a concept remains challenging. A casual search of YouTube for magnets reveals a staggering number of videos, interesting demos involving electric and permanent magnets, and entire channels devoted to various uses for magnets. It is far more difficult to find descriptions that can help students…

Video motion analysis allows tracing trajectories of objects in motion and is an established method in physics education. Tablet computers, with their integrated cameras, offer the opportunity to both record and analyze dynamic motions during experiments on a single device. This enables students to work without transitioning the data between…

The law of conservation of momentum can be applied to a wide range of processes whether it is the collision of subatomic particles, rocket propulsion, or the recoil of a cannon. In this experiment two technologies, the Arduino microcontroller and a PASCO smart cart, are used to create a movable rubber band launcher. The Arduino microcontroller is…

This paper reports our work on replacing lab report grading by post-online lab quizzes using Desire2Learn (D2L, an online course management software), specifically, how we circumvent some of the limitations imposed by D2L and the outcomes.

In a paper (posthumously) co-authored by Isaac Newton himself, the primacy of geometric notions in pedagogical expositions of centripetal acceleration has been clearly asserted. In the present paper we demonstrate how this pedagogical prerogative can inform the design of an experiment involving an accelerometer-equipped smartphone rotating…

Popular demonstrations commonly use stretched spandex fabric to illustrate the way in which curved spacetime mimics the force of gravity in general relativity. There are significant potential conceptual pitfalls to such an approach. In particular, it obscures the fact that most of what we ordinarily feel as gravity is due to the warping of time…

The photoelectric effect is one of the key experiments taught during first- or second-year university and high school modern physics courses. It is usually the first experiment to introduce light quantization and the concept of photons as "packets of energy." Here, we want to point out a widespread mistake concerning the interpretation…

Students should have a strong conceptual understanding of the connection between force and acceleration before they start working with applications and problem solving. This has been discussed in the literature. During these days of flipped classroom instruction, an at-home activity could be especially valuable. I will describe an experiment with…

For many years, Atwood's machine has been used to demonstrate, illustrate, or verify Newton's laws in introductory physics courses. It consists of two objects of different mass that are fastened to the ends of a string that hangs over a pulley. In an idealized situation, one assumes that pulley friction, the string's mass, and changes in the…

The second law of thermodynamics has various formulations. There is the "Clausius formulation," which can be stated in a very intuitive way: "No process is possible whose sole result is the transfer of heat from a cooler to a hotter body." There is also the "Kelvin-Plank principle," which states that "no cyclic…

The hearts of sports fans were stirred recently by the fastest-ever try scored in international rugby. Welsh winger Dafydd Howells crossed the Fijian try line to score a mere six seconds after Angus O'Brien had started the game with a kickoff, in one of the fixtures in rugby's Junior World Cup played on June 2, 2014, in New Zealand. This…

Values for physical constants are commonly given as abstractions without building strong intuition, and are too often utilized solely in the pursuit of more easily conceptualized properties. The goal of this experiment is to remove the obscurity behind Young's modulus by exploring the phenomena associated with it--namely, the frequency of a…