In introductory physics courses, within the context of studying Newton's laws, it is common to consider the problem of a body's "weight" when it is in free fall. The solution shows that the "weight" is zero and this leads to a discussion of the concept of weight. There are permanent free-fall situations such as astronauts in a spacecraft orbiting…

Demonstrating probabilistic outcomes using real-time data is especially well-suited to larger lecture classes where one can generate large data sets easily. The difficulty comes in quickly collecting, analyzing, and displaying the information. With the advent of wireless polling technology (clickers), this difficulty is removed. In this paper we…

When I was an undergraduate physics major, I would often stay up late with my physics major roommate as we would digest the physics content we were learning in our courses and explore our respective imaginations armed with our new knowledge. Such activity during my undergraduate years was confined to informal settings, and the first formal…

The speed of sound is a physical property that can be measured easily in the lab. However, finding an inexpensive and intuitive way for students to determine this speed has been more involved. The introduction of affordable consumer-grade high-speed cameras (such as the Exilim EX-FC100) makes conceptually simple experiments feasible. Since the…

Socratic dialogue-inducing (SDI) labs are based on Arnold Arons' half-century of ethnographic research, listening carefully to students' responses to probing Socratic questions on physics, science, and ways of thinking, and culminating in his landmark "Teaching Introductory Physics." They utilize "interactive engagement" methods and are designed,…

Describes the use of concept-centered minilabs in physics instruction. Finds this method successful in several courses taught by different instructors at Rutgers University. (CCM)

Finds that first-year college students can understand in detail the origin of the equivalent mass. Provides both a simple calculation derivation of this result as well as a noncalculus derivation. Argues that for every soft spring, the equivalent mass should be somewhere between m0/3 and m0/2. (CCM)

Describes Herschel's demonstration of interference arising from many coherent rays. Presents a method for students to reproduce this demonstration and obtain beautiful multiple-beam interference patterns. (CCM)

Describes how to build your own drop tower. Notes that these demonstrations are part of a portable and compact demonstration kit that fits entirely into a trunk, television and all. (CCM)

Studies the optimum launch angle for maximizing the long jump from a kinematical point of view. (CCM)

Describes a quantitative approach to the demonstration that the energy of a photon is proportional to its frequency. (CCM)

Dynamic field maps and contour curves provide a new way of depicting and analyzing the electric field of uniformly moving point charges. Presents an alternative way of graphically representing the electricity field of a uniformly moving point charge. (CCM)

Explains a change in sign convention for thermodynamic work. (CCM)

Analyzes the motion of a charged point particle started from rest near the center of a charged circular ring. (CCM)

Argues that using in-class worksheets are versatile and can be tailored to meet specific goals. Finds that worksheets are effective for confronting preconceptions, ensuring class participation, and increasing student/teacher interactions. (CCM)