It is a well known fact that the Earth carries a net negative charge that produces a downward electrostatic field. The present experiment shows how this field can be measured with a Field Mill which has been constructed from components readily available in the Laboratory. In fine weather conditions a value of 120 (±10) V m[superscript -1] was…

In an article in this journal, it was shown that air resistance could never be a significant source of error in typical free-fall experiments in introductory physics laboratories. Since projectile motion is the two-dimensional version of the free-fall experiment and usually follows the former experiment in such laboratories, it seemed natural to…

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…

A classic undergraduate introductory experiment is to measure the diffraction and interference pattern from single and double slits to determine slit width and separation. Studies show that Course-based Undergraduate Research Experiences (CUREs) can make science more inclusive when offered at the undergraduate level. Additionally, CUREs help…

To study the absorption of ultrasound in plexiglas we propose to use gadgets that are available to each student: an ultrasound humidifier, a liquid crystal display of a pad, a polaroid analyzer, a digital camera, a multimeter with thermocouple, and a stopwatch. These devices allow us to visualize a region in plexiglas where ultrasound is absorbed…

Newton's law of cooling describes an object whose temperature decreases exponentially with time. Because of its many applications, it is a frequent topic of introductory physics labs. In this article, I describe an experiment designed for the freshman year algebra-based physics course that applies this law to answering the question, "Why…

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 main objective of this paper is to provide an explanation on a conceptual level of how the Mirascope and the occurring image formation work. The physics behind a Mirascope--a well-known device consisting of two concave mirrors--is very complex. In literature, only either high level or very simplified and deficient explanations can be found.…

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…

It is generally accepted that education in the field of physics is possible only when one has received sufficient grounds for it. But physics is an attempt to understand the world around us. Everything one needs to study physics is an open mind and willingness to learn. It is also commonly thought that preschool-age children have a natural…

The microNet ([mu]Net) project aims at the development of an extended network of educational cosmic ray telescopes in the geographical area of western Greece. In the initial phase (2022-2023) of the project, 20 telescopes will be deployed in high school buildings, while more than 50 schools will attend the educational program of [mu]Net by…

Our study evaluates students' approaches to and perceptions of the use of hands-on at-home laboratory kits (HALK) experiments, open-source computer-based simulations (OSCBS), and their combination (OSCBS-HALK) in undergraduate introductory asynchronous online physics courses. Anonymous survey data from students who had completed online physics…

Mobile phones are a widely used platform for educational apps, mobile health, and a variety of chemical tests. Here, we are working on a mobile phone-based physics lab (mPhysics) that uses a mobile phone's capabilities to run simple physics experiments and demonstrations. While a mobile phone can be used to analyze magnetic and optical properties…

Take a selection of balls and marbles along to a nearby playground slide and let students investigate factors that may influence how balls accelerate down an inclined plane. Students can make hypotheses in small groups, plan investigations to test multiple possible explanations and draw conclusions about the importance of different variables. The…