Introduces a photogate arrangement using a photo-reflective sensor for air track experiments. Reports that the sensitivity to sunlight can be eliminated and a mechanically more convenient package produced. Shows the mounting, circuit, and usage of the photogate. (YP)

Examines preconceptions regarding several implicit vector characteristics that 15- to 17-year-old students possess just before taking their first physics course. Shows seven vector characteristics and three tasks for interviewing students. Presents the most common student preconceptions regarding each of the implicit vector characteristics. (YP)

Malawian children and young adults displayed sensitivity to static information for depth when stimulus objects subtended equal visual angles. When the more distant object was larger but subtended a smaller visual angle than the nearer, subjects tended to base judgments on retinal size. Motion paralax information increased accuracy of judgments of…

The key to learning is student involvement! This American Association of Physics Teachers/Physics Teaching Resource Agents (AAPT/PTRA) manual presents examples of two techniques that are proven to increase student involvement in your classroom. Based on the "5E" model of learning, exploratories are designed to get your students excited about the…

This paper reports on efforts to design a computer-based instructional unit for 7th grade students that would not only address state standards but would also provide some groundwork for the students' subsequent formal study of algebra. SimCalc Mathworlds software was used to explore the same motion from different perspectives. The overall…

Provides additional information on a demonstration described in the March 1981 issue of "The Physics Teacher" involving free-falling objects using styrofoam cups, rubber bands, and weights. Approaches the subject using free-body diagrams (included) and discusses the mechanism by which the weights are pulled into the cup. (JM)

An elementary formalism is developed for representing curved space-time which allows transparent qualitative explanation of general relativistic effects and is used to make a conceptual analysis of Einstein's principle of equivalence. A final section outlines a number of student activities. (Author/SK)

Examples of the application of compound pendulum theory to the practical measurement of the moments of inertia of human beings, farm tractors, and sailing boats are presented. Suggests developing laboratory experiments to measure moments of inertia of hockey sticks, golf clubs, and frisbees, among others. (Author/SK)

Describes a study which determined the prevalence of the non-Newtonian view among students (N=125) and to what extent their physics teachers (N=5) were aware of this prevalence. Includes methods used and summaries of typical responses to a paper-pencil, multiple-choice format questionnaire focusing on aspects related to force. (JN)

Explains that the result of collision experiments with a linear arrangement of several identical elastic balls cannot be predicted solely from the conservation laws and energy and momentum. Indicates that the system of balls must be capable of dispersion-free energy propagation. (Author/JN)

Different programs have been developed for the simulation of physics experiments by using TI-57 programmable calculators. Two of these programs, describing the simulation of a successive radioactive decay and the random motion of a gas molecule, are presented. (Author/SK)

Describes a systematic investigation of the understanding of velocity by students in introductory physics courses. Data were obtained using the individual demonstration interview, similar to the clinical interview. Results are reported for success of different populations in comparing velocities for two simultaneous motions. Implications for…

Presents an experiment to show the energy conservation principle using a bow. Describes how to measure the force and work of the bow and the initial velocity of an arrow. (YP)

Notes that the rigorous kinetic theory, based on the Boltzmann equation, does not yield exact results although some texts claim this to be so. Stresses that they should be presented as approximations with an indication that refinements in the values are possible. (MVL)