Provides background information procedures, and results for the photochemical synthesis and reactions of nitrosomethane dimer. The experiments described have shown a high degree of reliability with student use and are suggested to illustrate some problems of physical and organic photochemistry. (Author/JN)

An air-track and glider system used to demonstrate Newton's second law is described. Advantages of using the system are included. (SK)

Theory of nuclear magnetic resonance spin-spin coupling constants and nature of the three types of coupling mechanisms contributing to the overall spin-spin coupling constant are reviewed, including carbon-carbon coupling (neither containing a lone pair of electrons) and carbon-nitrogen coupling (one containing a lone pair of electrons).…

The acid-catalyzed hydrolysis of N-vinyl pyrrolidone provides a simple spectrophotometric kinetic experiment to introduce general acid catalysis, solvent isotope effects, and other aspects of ionic reactions in solution in advanced courses. The Bronsted equation and concept of linear free-energy changes is also covered. (SK)

Explains that the efficiency and the useful power available from a windmill turbine, of a laminar-flow model, will vary due to rotational kinetic energy of the downwind stream and turbulent mixing from outside the boundaries of the idealized stream. (GA)

Describes a simple demonstration that shows the change in molecular density and the reduction in pressure of air in a centrifugal field. Uses two circular disks with the same radius and rotating with the same angular velocity, in loose mutual contact, around their symmetry axis. (GA)

Discusses how the adiabatic law for ideal gases can be derived from the assumption of a Maxwell-Boltzmann (or any other) distribution of velocities--in contrast to the usual derivations from thermodynamics alone, and the higher-order effect that leads to one-body viscosity. An elementary derivation of the adiabatic law is given. (Author/DS)

Describes a clock reaction resulting from the reaction of paraquat with base. (CS)

By using the method of moments, it is shown that several important and apparently unrelated theorems describing average properties of stochastic systems are in fact particular cases of a general law; this method is applied to generalize the virial theorem and the fluctuation-dissipation theorem to the time-dependent case. (Author/SK)

Describes a student investigation of a reverse flame in a atmosphere of methane that won second place in the physics division of the International Science and Engineering Fair. Includes a discussion of falling and fracturing behavior, specifically dealing with chimneys, trees, pencil point, stirring rods, and chalk. (BT)

Discusses several different methods that performers (divers and trampolinists) use to initate somersaults and twists and presents concrete examples of each method. Presents and evaluates quantitative calculations using information about the moments of inertia, mass, etc., of "typical" performers. (Author/GA)

Using a photon-counting technique, finds the angular distribution of emitted and detected power and the total radiated power of an arbitrary moving source, and uses the technique to verify the predicted effect of the earth's motion through the cosmic blackbody radiation. (Author/GA)

The author argues that a Lagrangian that yields equations of motion for a damped simple harmonic oscillator does not describe this system, but a completely different physical system, and constructs a physical system that the Lagrangian describes and derives some of its properties. (Author/GA)

Investigates the "photographic" appearance of a cube moving at relativistic speeds, and shows that it depends upon whether the camera is held fixed with the optic axis perpendicular to the direction of motion or panned to follow the cube as it moves. (Author/GA)

Following a delineation of thermoluminescence from a historical perspective and a qualitative description of the process, a treatment of the kinetic process based on a simple model is presented. This treatment model is adequate for the purpose of identifying the essential requirements in instrument design. (BT)