Advocates the use of subscripts in the formula for relativistic velocity addition to minimize student confusion. (WRM)

Offers a relatively simple analysis of the asymmetrical "sticking" and rolling behavior of two balls, one steel and one rubber, on an incline. Describes an Interactive Physics (TM) simulation designed to study the problem and gives rough experimental results. (WRM)

Describes the construction and use of a set of "relativistic metersticks" that represent the apparent lengths of a meterstick passing a stationary observer at relative speed v/c. (WRM)

Presents an activity that involves dropping spherical party balloons onto a sonic motion sensor to show that the force associated with the air resistance is proportional to both the square of the velocity and the cross-sectional area of the balloon. (Author/WRM)

Describes how to use the computer algebra system (CAS) Mathematica to analyze projectile motion with and without air resistance. These experiments result in several conjectures leading to theorems. (Contains 17 references.) (Author/ASK)

Describes an activity that explores the relationship between the impulse and the distance traveled by a projectile. (WRM)

Presents two projects in which students investigate (1) what things affect how far someone can throw a tennis ball?, and (2) is your mobile phone frying your brain? (YDS)

Infants' ability to track temporarily occluded objects that moved on circular trajectories was investigated in 20 infants using a longitudinal design. They were first seen at 6 months and then every 2nd month until the end of their 1st year. Infants were presented with occlusion events covering 20% of the target's trajectory (effective occlusion…

A fundamental question of perceptual development concerns how infants come to perceive partly hidden objects as unified across a spatial gap imposed by an occluder. Much is known about the time course of development of perceptual completion during the first several months after birth, as well as some of the visual information that supports unity…

Measurement of eye movements is a powerful tool for investigating perceptual and cognitive function in both infants and adults. Straightforwardly, eye movements provide a multifaceted measure of performance. For example, the location of fixations, their duration, time of occurrence, and accuracy all are potentially revealing and often allow…

Everything moves. Even apparently stationary objects such as houses, roads, or mountains are moving because they sit on a spinning planet orbiting the Sun. Not surprisingly, the concepts of motion and the forces that affect moving objects are an integral part of the middle school science curriculum. However, middle school students are often taught…

When watching a small child with a toy car, it is seen that interest in motion comes early. Children often suggest speed through sounds such as "RRRrrrRRRooooommMMMmmmm" as the toy car is made to speed up, slow down, or accelerate through a turn. Older children start to consider force and motion studies in more detail, and experiences in school…

In this descriptive case study, we describe a 10-day program of study of motion down inclined planes during which a class of 21 second graders investigated scientific relations such as mass and speed, speed and momentum, and mass and momentum via both text-based experiences ("second-hand investigations") and hands-on, materials-based experiments…

A pendulum "engine" with dynamic parameters can be created and pendulum functions manipulated and analyzed using interactive elements in Flash. The effects of changing the damping (convergence) properties, initial release angle and initial velocity conditions can be explored. The motions then can be digitized using the Flash Digitizer 1.1,…

Many studies have analysed how goal directed movements are corrected in response to changes in the properties of the target. However, only simple movements to single targets have been used in those studies, so little is known about movement corrections under more complex situations. Evidence from studies that ask for movements to several targets…