Presents a laboratory exercise designed to introduce graphical extrapolation. Major advantages of the method are in its simplicity and speed. The only measuring devices are a centimeter ruler and a micrometer caliper to check wall thickness. (JN)

A procedure that allows students to view an entire bacterial growth curve during a two- to three-hour student laboratory period is described. Observations of the lag phase, logarithmic phase, maximum stationary phase, and phase of decline are possible. A nonpathogenic, marine bacterium is used in the investigation. (KR)

Presents a simple qualitative system for sketching all manner of acid-base titration curves, requiring only the approximate values of the acid or base ionization constants. (WRM)

Presents a method for graphically illustrating Le Chatelier's principle, suitable for the general chemistry undergraduate. (CS)

Demonstrates how a simple graph can be effectively used in teaching the concept, measurement, and use of humidity. Science activities for upper elementary, secondary, and higher education students are suggested and definitions of terms are presented. (Author/DB)

Introduces a method for constructing phylogenies using molecular traits and elementary graph theory. Discusses analyzing molecular data and using weighted graphs, minimum-weight spanning trees, and rooted cube phylogenies to display the data. (DDR)

A quantitative application of magnetic braking performed with an air track is described. The experimental measurement of the position of the glider as a function of time is calculated. (KR)

Presents a pre-lab exercise, an experimental setup, and discussion of computer-generated graphs that can be used to study the motion and energy of a bouncing ball. (WRM)

Presented is an activity in which a mystery setting is used to motivate students to construct their own decay curves of melting ice used as an analogy to radioactive decay. Procedures, materials, apparatus, discussion topics, presentation, and thermodynamics are discussed. (CW)

Features an assignment involving average monthly temperatures that can serve as an example of curve-fitting for a periodic function. (WRM)

Proposes that introductory physics courses extend the analysis of one-dimensional motion to a more sophisticated level. Gives four experimental setups and graphical analysis of the distance, velocity, and acceleration in the vertical and horizontal directions. (WRM)

According to historical stories, the Saxons placed a bowl with a hole in its bottom in water and used the time it took the bowl to submerge to limit orations. Describes a science activity in which students find a relationship between the diameter of the hole and the time to submergence. (WRM)

Uses a TI-82 graphics calculator to model the air drag of plastic, wood, cork, and foam balls during projectiles experiments. Provides equations and typical data table. (MVL)

Describes a physics laboratory exercise that focuses on an idea common to all scientific disciplines; that is, there are scaling laws that relate one measurable physical variable to another. (WRM)

An approach to teaching electrochemical driving force that helps students comprehend the forces that govern ion flux across biological membranes and sets the stage for more elaborate analysis of biochemical signals is presented. Background information and two sample problems and answers are included. (KR)