Presents a three-dimensional analysis of the relative speed before and after a two-body elastic collision, based on the concept of a Galilean invariant. (JRH)

Presents experiments that use Microcomputer Based Laboratory (MBL) techniques to enable freshmen physics students to investigate complex systems, such as nonlinear oscillators or coupled harmonic oscillators, at a level appropriate for an independent project. (JRH)

Provides instructions for the construction and launch of a two-liter plastic soda-bottle rocket and presents the author's theory of their motion during launch. Modeled predictions are compared with actual experimental data. Explains theory behind the motion of a water rocket during launch. (LZ)

Presents an activity that enables students to answer for themselves the question of how fast a body must travel before the nonrelativistic expression must be replaced with the correct relativistic expression by deciding on the accuracy required in describing the kinetic energy of a body. (ZWH)

Considers using a football game to provide a group activity on physics reasoning. Groups determine how long the coin toss was in the air, distance of kickoff, velocity of ball leaving the tee, maximum height of ball, force applied to the ball when passed by the quarterback, etc. Provides possible solutions to each question. (MVL)

Discusses the application of the rule of allowing the car in front to have a two-second lead. Notes that as speed doubles, stopping distances increase by four. Provides a table of stopping distances including reaction distance, braking distance, total stopping distance, and two-second rule distance. (MVL)

Presents data from two studies determining the validity of various measures of physical activity in preschool children. One explored how certain measures of activity predicted observed behavior. The other examined the Caltrac motion sensor's predictive validity. Results indicate the Caltrac monitor is sensitive to children's individual differences…

Assessed infants' detection of relative motion between a target and its surrounding static reference features in two experiments. Found evidence for 8- and 20-week-olds' detection of a moving target, and a target and surrounding reference features moving in opposite directions. Twenty-week-olds detected a target that moved faster and in the same…

Seven experiments involving a total of 203 college students explored a form of object-specific priming and established a robust object-specific benefit that indicates that a new stimulus will be named faster if it physically matches a previous stimulus seen as part of the same perceptual object. (SLD)

Reviews two projects studying the nature of mental representations of space induced entirely by language. The first project investigates perspective in descriptions of large-scale (e.g., convention center, town) space. The second project investigates mental representations of objects located immediately around the body. (37 references) (KRN)

Discusses how the Galilean balance equilibrium model can be used in the physics classroom to provide students with a model of intelligibility that would unify their thinking about motion and, at the same time, provide them with a general procedural schema for solving motion problems. (ZWH)

A procedure for estimating the speed and distance of plane, assuming the speed of sound and the velocity of the plane are constant, is described. (KR)

A procedure for measuring the speed of light using the assumption that the frequency of light remains unchanged as it moves from one medium to another is presented. A laser with a known wavelength and frequency in air was used as a light source. (KR)

A task involving movements with either hand to near or far targets was employed with 16 adults with mental retardation (9 of whom had Down's syndrome). Specific features of the movement were precued. Both groups were able to use advance information to reduce movement preparation time and were not limited by a fixed-order movement preparation…

Examined whether young infants produced differentially organized hand and arm actions in relation to affective expressions when the infants were presented with social and nonsocial stimuli. (PCB)