Describes three demonstrations: (1) "A 'Rocket' Cart" (using a fire extinguisher and a child's truck); (2) "Angular Momentum Conservation" (providing materials and calculations); and (3) "Cavendish Experiment" (including the building method and examples of calculations). (YP)

Describes an experimental sequence using the force probe to develop the relationship between net force and acceleration. (PR)

Discusses the principles of magnetic levitation presented in the physics classroom and applied to transportation systems. Topics discussed include three classroom demonstrations to illustrate magnetic levitation, the concept of eddy currents, lift and drag forces on a moving magnet, magnetic levitation vehicles, levitation with permanent magnets…

Describes a set-up for sending the infrared signal from a common remote control device to an oscilloscope in order to "see" the infrared signal. (WRM)

Describes the construction and use of a magnetic needle that is stronger than those conventionally used for experiments with electromagnetism. (WRM)

Describes the setup of a system that allows vibrations in two dimensions to demonstrate polarization states of light and particle spin. (WRM)

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)

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 versatile mount for Slinky wave demonstrator and dynamics experiments using pool balls which have been altered by various means such as hollowing out or filled with lead. Suggests tightening screw holding motor clamp to prevent random speed fluctuations in ripple tanks. (JN)

The author describes activities he uses with secondary school science students to learn about their reasoning. (Author/SA)

Errors found in a common physics experiment to measure acceleration resulting from gravity using a linear air track are investigated. Glider position at release and initial velocity are shown to be sources of systematic error. (CW)

Describes an exercise designed for an introductory level calculus-based physics class. Presents a problem on why a rod dipped in water is stable when it is oriented at an angle with the vertical. Discusses qualitative understanding, mechanical understanding using equations, and experimental verification of the problem. (YP)

Describes the manufacturing method for a high-temperature ceramic superconductor. Presents detailed procedures and pictures showing the manufacturing process. (YP)

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)

Discussed is a method of measuring the coefficient of linear expansion of a solid. Getting many data points, using a computer program using the least square fit technique, and modifying the apparatus are described. (YP)