Explains the concept of jerk and resolves it, for planar motion, into two components: tangential-normal and radial-transverse. Expresses the normal component in terms of an affine differential invariant, the aberrancy. Uses aberrancy properties to establish geometrical properties of the jerk vector for plane motion. (GA)

Discusses the criteria and procedure for optimizing the performance of Archibald rubber-band heat engines by using the appropriate choice of dimensions, minimizing frictional torque, maximizing torque and balancing the rubber band system. (GA)

Shows using the special theory of relativity, how a body acted upon by a force with positive components could have one or two negative acceleration components. (GA)

Includes eleven short notes, comments and responses to comments on a variety of topics such as uncertainty in a least-squares fit, display of diffraction patterns, the dark night sky paradox, error in the dynamics of deformable bodies and relative velocities and the runner. (GA)

Obtains the orbits with reference to the center of mass of two bodies under mutual universe square law interaction by use of the eccentricity vector which is equivalent to the Lenz vector within a numerical factor. (Author/SL)

Provides a detailed discussion of a Lagrange formalism in classical momentum space. (SL)

Described is a novel approach to the teaching of projectile motion of sixth form level. Students are asked to use an analogue circuit to observe projectile motion and to graph the experimental results. Using knowledge of basic dynamics, students are asked to explain the shape of the curves theoretically. (Author/MA)

Demonstrates that investigating coriolis effects in a fixed frame leads to a clearer understanding of the physical nature of the phenomenon. (SL)

Examines the motion of a particle in a noncentral potential using the action-angle formalism. (SL)

Describes a method for demonstrating harmonic motion which utilizes a low frequency oscillator and three oscilloscopes. (SL)

Four-year-olds were reliably accurate about movement potentials for the categories of mammals, nonmammalian animals, statues of animals, wheeled vehicles, and multipart, rigid objects. The three-year-olds' scores were significantly above chance in all categories but animals. Analyses showed that children were concerned about the cause of movement…

Investigates whether elementary school children can successfully execute a mental rotation on Marmor's state-comparison task without knowledge of logical sequence relations, whereas such knowledge is required to construct or evaluate external representations of the successive states in a rotation movement. (HOD)

Describes an apparatus for an experiment on winding motion in three dimensions. Discusses theory and provides a calculation example. (JM)

Investigates the perceptual basis of metaphor by asking 5-, 7-, and 10-year-old children and adults to pair and discuss films of natural objects, both stationary and moving. Concludes that motion information makes metaphoric similarity relatively easy to perceive and influences the form of descriptive metaphors. (Author/CB)

Examines, in two experiments, 5-month-old infants' sensitivity to auditory-visual specification of distance and direction of movement. One experiment presented two films with soundtracks in either a match or mismatch condition; the second showed the two films side-by-side with a single soundtrack appropriate to one. Infants demonstrated visual…