The various aspects of projectile motion have been analyzed many times in this journal. As a sample, over the years, authors have investigated particular details of the path of a projectile and different situations for launching projectiles. Others have written about a nifty way to determine the maximum height of a projectile, finding the range of…

X-rays are such an important and familiar part of the electromagnetic spectrum, but is there a way to safely bring x-rays into your lecture? The demo team at the University of California at Berkeley seems to have managed this. They have an x-ray safe box that they use to produce a live x-ray image on a fluorescent screen. In this article, we…

There are hundreds of satellites in orbit around Earth. Readily available data about them can be a treasure trove for investigations by students at all levels. Orbital parameters and energy changes can be explored. Many of these satellites transmit signals that can be detected by an inexpensive radio receiver--a scanner--designed to receive FM…

Aristotle's wheel paradox is a fascinating example of a classical puzzle that can pique a student's interest. The existing explanations in the literature are limited to discussions of the wheel trajectory; in this paper, we study the paradox from the viewpoint of motion decomposition, an approach we consider more intuitive. The motion of the point…

Electricity has shaped modern civilization in a way few other discoveries have. Nonetheless, few students successfully develop a basic understanding of voltage, current, and resistance or their mutual relationship in simple DC circuits. Despite teachers' best efforts in the classroom, so-called "alternative conceptions" often prevail…

The electric field inside a uniformly charged long cylindrical shell is a standard example discussed in introductory university physics. The field is zero inside the cylinder; outside of the cylinder, the field behaves like a long wire at the center carrying the same amount of charge per unit length, analogous to that of a uniformly charged…

A Finderscope is a low-power telescope with a relatively large field of view. It has the same line of sight as the main telescope, helping the main telescope easily find the target. One of the differences between a telescope and a finder is that the finder has crosshairs to aid in accurately pointing at a target. You can see the crosshairs and the…

In conventional physics teaching, acceleration measurement is demonstrated using motion sensors and carts on inclined tracks, and relevant data are collected using specific professional software. This approach entails the connection of computers and interface boxes, and requires high cost and large space. Air-track carts can be used to perform…

Problems involving chains, cables, or ropes that are dropped, folded, or pass around pulleys attract ongoing interest, in part because they can become variable-mass situations if the chain is partitioned into sections for analysis. Less attention has been paid to trying to intentionally project the end of a string as far as possible. Here we…

In this paper, an experimental setup composed of a color-mixing device, power supply, and spectrometer is developed. This setup is available for students to do hands-on color mixing with red, green, and blue light in undergraduate labs. LED volt-ampere and spectrum characteristics are investigated. The apparatus was used to perform additive color…

In this article, we present an intriguing experimental exercise that does not fall foul of improper use of instrumentation. The activity is designed as an electronics exercise where the role of the instruments in the measurement of the RC time constant is considered. Essentially, we study the accuracy and precision of a measurement of the RC time…

There are many examples of using smartphones in physics experiments. Students and teachers can easily perform many physics experiments with the help of smartphone sensors, even experiments for which high-cost materials are needed. There are different types of such experiments in which various kinds of sensors are used. Many physical quantities can…

Quantum computers are at the forefront of computing; however, few people understand how they work and their capabilities. We present two versions of an interactive activity designed for high school students (ages 13 to 18) that introduce a core quantum concept--"entanglement." The first version illustrates a simple connection between two…

It is often challenging for physics instructors to dedicate time during a course to engage students in developing strategic approaches to learning in addition to problem-solving skills and content knowledge. In this work, we introduce a simple modification to our teaching practice with the purpose of fostering student development of self-regulated…

Most physics courses begin with one-dimensional kinematics, which is usually restricted to the case of constant acceleration. Here we report a unique exercise for an introductory algebra-based physics course involving the running and non-constant acceleration of the theropod dinosaur "Dilophosaurus wetherilli" and the world-famous…