Rhythmic groups of cyclical movements--action cycles--were identified during interactions between adults and subjects (12 children, aged 8-18, and 6 young adults with profound mental handicap). Subjects performed similar actions for apparently similar reasons at similar rates to their caregivers, giving strong indication of a biologically robust…

Evidence is presented negating the theory that gravitoinertial force is perceived. It is suggested that spatial orientation is based on information derived from patterns of motion of the organism, the surface of support, and compensatory actions of the organism. Recommendations for further research are outlined. (SLD)

Reports on the implementation of a relatively low-cost, versatile, and intuitive system to teach basic mechanics based on the use of a Charge-Coupled Device (CCD) camera and inexpensive image-processing and analysis software. Discusses strengths and limitations of CCD imaging technologies. (JRH)

Presents a few examples of not-so-traditional problems that can be very helpful in teaching some particular concepts or approaches in physics. Problem sets include vector addition and vector components, reference frames, and choosing the right approximations. (JRH)

Describes an experiment to study the motion of a rocket-propelled vehicle over the entire duration of the engine burn using a video system with a frame-by-frame playback and a Sonic Ranger for ultrasonic position movements. Enables students to study the impulse-momentum principle and the effects of a time-varying force. (JRH)

Provides a description, photograph, and relevant analysis of a simple device for demonstration of rotational motion. (LZ)

By developing a sequence of mathematical models of harmonic motion, shows that mathematical models are not right or wrong, but instead are better or poorer representations of the problem situation. (MKR)

Presents the Astro-Blaster as a method of the laws of conservation of momentum and energy during the creation of a supernova. Several elastic balls are aligned for a drop, followed by multiple collisions which result in the top ball reaching tremendous heights relative to the drop height. (JRH)

Provides a motion activity where a student walker is timed as he passes various students along a set course. The motion of the walker changes with each trip. The findings are then graphed and the results discussed. (MVL)

Discusses the hydrodynamic reasons why a riverbed meanders through a plain. Describes how water movement at a bend in a river causes erosion and changes in the riverbed. Provides a mathematical model to explain the periodic shape of meanders of a river in a plain. (MDH)

Fifteen true-false statements are provided that are to be used to spur discussion and arguments about the concept of motion. Each statement is carefully worded to sound plausible, but each one attacks some misunderstanding common to students who are encountering Newton's mechanics for the first time. (KR)

Evaluates the technical efficacy of the V-Scope in measuring motion produced by a phonograph turntable, a template furnished by the manufacturer, a free-fall apparatus, some pendula, a gyroscope, and three air tables. Concludes that the V-Scope gives excellent results and is easy to use. (MDH)

A model of the inelastic collision between two spheres rolling along a horizontal track is presented, taking into account the effects of frictional forces at impact. This experiment makes possible direct estimates of the coefficients of restitution and friction. (Author)

This study compared the batting swing of two skilled congenitally blind beep baseball players to a perfect kinetic-link model for the batting skill. It found that the subjects used a modified batting technique and that there was an inverse relationship between the subjects' performances and the kinetic-link model. (Author)

Describes a study designed to identify the various reasoning procedures used by students (n=229) in comparing the average velocities of two moving bodies; compare the differences among the procedures used by students at different school levels; and analyze the relationship between automatic and human diagnoses to identify diagnostic errors of the…