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…

Within physics education research (PER), inductive teaching strategies (e.g., inquiry-based teaching) have long been a goal. Yet others do not seem to be convinced that consensus exists with respect to the goals of physics education and identify three possible goals as: (1) to teach practical, factual knowledge, (2) to develop deep understandings…

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…

Here is presented an interesting problem that can be used to introduce students to a variety of physics topics including non-inertial frames and frictional forces, rotational dynamics, and damped oscillations; the normal force also appears, but not in its usual guises. The problem is a generalized version of problem 3.34 presented in the…

Shadows produced by sunlight reflected from convex surfaces can be very well defined. This article provides an explanation for this phenomenon as well as a demonstration/lab activity for students to investigate properties of shadows made from sunlight reflected by a curved surface.

Astrophotography has been responsible for the discovery of planets, solar systems, stars, and several other celestial objects, which directly helps with expanding our knowledge about the universe and creating scientific models for nature. Practical techniques have been extensively described, including Covington, who has published an extensive…

We describe an educational activity that can be completed with mobile media devices in order to understand the working principle of a pair of tuning forks, from the Historical Collection of Physics Instruments of the University of Palermo, and how they were used to explain acoustic interference and beats with the Lissajous optical method. This…

Exploding pumpkins with rubber bands remains a popular demonstration of the conversion of spring potential energy into kinetic energy. Videos of laughing and squealing children and adults being pelted with pumpkin fragments have millions of hits on YouTube, and the activity has even been featured on talk shows like "The Tonight Show Starring…

The ubiquitous bouncy ball, or "superball," is an engaging child's toy that has endured for more than 50 years. But what makes a bouncy ball so uniquely suited to its name? Steel balls, for example, are more highly elastic than are butadiene bouncy balls. Yet it is butadiene balls, and not steel balls, that appear in toy stores and…

What do you get when you cross a rubber band with a photocopier? You get a whole series of physics lessons and some great images! It's easy to get this activity up and running, be amazed, and apply it to any number of scientific concepts. It lends itself to a whole host of investigations. This easy-to-do activity can also be aligned to NGSS…

Kinesthetic experiences in the classroom seek to engage students by muscle movement, touch, or some form of physical activity. In this article, I describe an active learning session wherein students develop a qualitative understanding of center of mass and support forces using their sense of touch. The set of activities detailed here is based on a…

Calls for reform to instructional labs mean many instructors and departments are facing the daunting task of identifying goals for their introductory lab courses. Fortunately, the American Association of Physics Teachers (AAPT) released a set of recommendations for learning goals for the lab to support lab redevelopment. Here we outline the…

Some teenagers are exploring the outer perimeter of a castle. They notice a spy hole in its wall, across the moat a horizontal distance "x" and vertically up the wall a distance "y." They decide to throw pebbles at the hole. One girl wants to use physics to throw with the minimum speed necessary to hit the hole. What is the…

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…

The author has acquired a yellow laser with the specific wavelength of 589 nm. Because this is the first time such a laser has been discussed in this journal, I feel it is appropriate to provide a discussion of its function and capabilities. Normal laser safety should be employed, such as not pointing it into eyes or at people, and using eye…