Describes the construction of the Reduced-Gravity Demonstrator, which can be used to illustrate the effects of gravity on a variety of phenomena, including the way fluids flow, flames burn, and mechanical systems behave. Presents experiments, appropriate for classroom use, to demonstrate how the behavior of common physical systems change when…

Presents a simple and inexpensive procedure for determining the moment of inertia of a physical pendulum both experimentally and analytically. The simplicity of the apparatus enables students to easily change parameters and obtain a wide variety of measurements. (JRH)

Presents a laboratory exercise on photosynthesis suitable for high school biology. Allows students to perform the experiments with easily obtainable materials and within a lengthened period. Includes photosynthesis lab prep notes for teachers. (JRH)

Presents an experimental approach to illustrate that the thermodynamic properties of a system can be considered as the average of mechanical variables. Discusses the Knudsen effusion method to count the number of molecules, vapor pressure, the piezoelectric effect, the experimental setup, and sample experimental results. (JRH)

Presents an activity to determine whether the radioactivity of a pure potassium salt is directly proportional to the amount of potassium in it and whether this could be used as a method of analysis for potassium in a solid. (MKR)

Describes a laboratory exercise used by botany students to verify their textbook's teaching about photosynthesis and respiration. (ZWH)

Describes an inexpensive replacement for the gel matrix, agarose, to aid teachers in reducing the cost of supplies needed to perform gel electrophoresis experiments. (ZWH)

Describes a simple way for groups to view a demonstration of Brownian Motion using a laser and liquid suspension. (AIM)

Discusses the behavior of the current near the end of the paper in the electric-field mapping experiment and approaches to solving problems associated with this behavior. Presents programs that can be used to model the boundary condition computationally. (JRH)

Describes an experiment to measure the speed of air in the air jet caused by blowing air through a drinking straw. (JRH)

Describes a diffraction experiment that uses circular holes salvaged from nonaerosol hair spray bottles to produce spectacular circular interference fringes. (JRH)

Presents a model experiment for quantifying phagocytosis using earthworm coelomocytes and determining the optimum length of time necessary to obtain maximum phagocytosis. Involves incubating coelomocytes from invertebrates with an antigen, staining the cells, counting the number of antigen particles ingested, and measuring the effect of different…

Describes the preparation of a simple microbiological medium using inexpensive materials routinely available in any supermarket. Discusses inoculation of the medium and colony examination. (JRH)

Describes an alternative technique for determining the molar volume of hydrogen from the metal-acid reaction in which the metal sample is encased in a specially prepared cage and a pipette filler is used to fill an inverted burette with water. Eliminates some difficulties encountered with the conventional technique. (JRH)

Details a simple quantitative experiment to measure the percent of oxygen in air. (DKM)