Shows that von Neumann's mathematical theorem on composite systems acquires a transparent physical meaning with reference to a suitable physical example; a composite system in a state of definite angular momentum. Gives an outline of the theorem, and the results are restated in Dirac's notation, thus generalizing von Neumann's results which were…

Describes some experiments of parametric effects intended to be disigned by the students themselves and shows how to introduce parametric interactions and nonlinearities to the students in a simple manner. (GA)

A qualitative demonstration of wave motion along a linear spring is being used, quantitavely, to present three methods of measuring the phase velocity of the waves. (GA)

Describes the criteria used to devise a test to evaluate the experiment-oriented investigative and problem-solving capabilities of students entering an introductory physics course. (Author/GA)

Describes an apparatus which allows one to study the speed distribution, the gravitational distribution, and the mean free path of steel balls agitated into two-dimensional motion through collisions with the moving walls of their enclosure. (Author/GA)

Analyzes projectile motion using symmetry and simple geometry. Deduces the direction of velocity at any point, range, time of flight, maximum height, safety parabola, and maximum range for a projectile launched upon a plane inclined at any angle with respect to the horizontal. (Author/GA)

Studies the elastic linear collision of three bodies of equal mass. One of the bodies is incident on the other two which are at rest and in contact with each other. (GA)

Listed are errors students make by accepting misconceptions about pressure and precautions teachers might take to avoid fostering those misconceptions. Misconceptions discussed include pressure as a measure of energy per unit volume, fluid flow only from high to low pressure, and the lack of pressures lower than a vacuum. (CW)

Discusses the change in pressure as a balloon expands. Describes the pressure change in a spherical soap bubble and a rubber membrane on the tube. Provides demonstrations when two balloons are connected by a tube. Lists five further reading materials. (YP)

Discusses pupil misconceptions concerning forces. Summarizes some of Assessment of Performance Unit's findings on meaning of (1) force, (2) force and motion in one dimension and two dimensions, and (3) Newton's second law. (YP)

Explains the variables involved when stopping a car on various types of pavement, braking schemes and additional concerns. (RT)

Four questions related to rain concerning aerodynamic drag force, pressure from the impact of raindrops, impact of wind on the pressure, and stopping force extended on the car by the water are proposed. (YP)

Investigates the nature of college student difficulties with negative values of velocity by using interviews. Discusses graphical representation of negative values of velocity and interpretations of graphs involving negative values of force. Suggests some instructional implications from the discussion. (YP)

Described is an experiment for measuring the coefficient of restitution with a meter stick, balls of different types, and scraps of material for the plates. Provides the experimental procedure and an apparatus diagram. (YP)

Examines 52 fifth graders' written and oral responses to determine the impact of a scientific demonstration on their understanding of air pressure. For one-third of the children, the demonstration reinforced previous understanding. Recommendations for using demonstrations to promote children's scientific understanding are presented. (ZWH)