Over the past 25 years, the Davidson College Physics Department has developed small computer programs called Physlets. These programs were written in Java and distributed as Java applets embedded in HTML pages. Physics teachers from around the world used Physlets to author interactive computer-based curricular materials for the teaching of…

Educators have found that kinesthetic involvement in an experiment or demonstration can engage students in a powerful way. With that as our goal, we developed three activities that allow students to connect with and quantitatively explore key physics principles from mechanics with three fun physical challenges. By presenting these activities as…

In this article we compare students' understanding of vector concepts in problems with no physical context, and with three mechanics contexts: force, velocity, and work. Based on our "Test of Understanding of Vectors," a multiple-choice test presented elsewhere, we designed two isomorphic shorter versions of 12 items each: a test with no…

The Advanced Placement® (AP®) Program offers high school students the opportunity to take rigorous coursework in high school and receive college credit for AP Exam scores that meet or exceed the requirements of their attending institution. Students receiving AP credit are typically exempted from an introductory level course or series of courses…

Problem solving is a critical element of learning physics. However, traditional instruction often emphasizes the quantitative aspects of problem solving such as equations and mathematical procedures rather than qualitative analysis for selecting appropriate concepts and principles. This study describes the development and evaluation of an…

As we typically teach in an introductory mechanics course, choosing a "good" coordinate frame with convenient axes may present a major simplification to a problem. Additionally, knowing some conserved quantities provides an extremely powerful problem-solving tool. While the former idea is typically discussed in the context of…

Poggendorff showed experimentally, in the middle of the 19th century, that the weight of an Atwood machine is reduced when it is brought to motion. His experiment has been revisited from time to time, making use of instrumentation that reflects the technological development of the moment. In this paper, the evolution of the experiment is briefly…

My favorite exam question comes from the final exam in an introductory mechanics course: "A rolling 31 ton railroad boxcar collides with a stationary flatcar. The coupling mechanism activates so the cars latch together and roll down the track attached. Of the initial kinetic energy, 38% dissipates as heat, sound, vibrations, mechanical…

As presented in physics textbooks, as well as in a few papers, the typical example of an induced motional electromotive force e[subscript mot] = "Blv" consists of a conductive rod of length "l" frictionlessly sliding with speed v along parallel wires within an orthogonal and constant uniform magnetic field of magnitude…

We have developed much simpler cloud chambers that use only ice and cooking salt instead of the dry ice or ice gel pack needed for the cloud chambers produced in our previous work. The observed alpha-ray particle tracks are as clear as those observed using our previous cloud chambers. The tracks can be observed continuously for about 20?min, and…

Trampolines can be found in many gardens and also in some playgrounds. They offer an easily accessible vertical motion that includes free fall. In this work, the motion on a trampoline is modelled by assuming a linear relation between force and deflection, giving harmonic oscillations for small amplitudes. An expression for the cycle-time is…

Maxwell's needle apparatus is used to determine the shear modulus (?) of the material of a wire of uniform cylindrical cross section. Conventionally, a single observation is taken for each observable, and the value of ? is calculated in a single shot. A modification to the above apparatus is made by varying one of the observables, namely the mass…

A teacher learning how to write test questions (test items) will almost certainly encounter item-writing guidelines--lists of item-writing do's and don'ts. Item-writing guidelines usually are presented as applicable across all assessment settings. Table I shows some guidelines that I believe to be generally applicable and two will be briefly…

The uniting of two seemingly disparate subjects in the classroom provides an interesting motivation for learning. Students are interested in how these subjects can possibly be integrated into related ideas. Such is the mixture of physics and music. Both are based upon mathematics, which becomes the interlocking theme. The connecting physical…

How physics can be made interesting is a question that needs no answer. That's because physics is interesting! It's a field of study jam-packed with fascination and wonder. The general public has an enormous thirst for physics knowledge, as indicated by the great numbers who purchase science magazines and books and watch "NOVA" and other…