The collision of a ball with the end of a barbell illustrates the combined conservation laws of linear and angular momentum. This paper considers the instructive but unfamiliar case where the ball's incident direction of travel makes an acute angle with the barbell's connecting rod. The analysis uses the coefficient of restitution generalized to…

These 6 experiments explored the ability of moving random dot patterns to attract attention, as measured by a simple probe-detection task. Each trial began with random motion (i.e., dots linearly moved in random directions). After 1 s motion in 1 hemifield became gradually coherent (i.e., all dots moved up-, down-, left-, or rightwards, or either…

Learning in Motion (LIM) was a European project involving seven partners in five countries: Sweden, Finland, Latvia, Germany and Greece. The project focused on inclusion and access to outdoor education and was financed by the European Commission within the framework of the Socrates-Grundtvig Programme. The aim of the project was to explore if and…

More than 25% of accidents are rear-end collisions. It is essential to identify the factors that contribute to such collisions. One such factor is a driver's ability to respond to the deceleration of the car ahead. In Experiment 1, we measured effects of optic flow information and discrete visual and auditory warnings (brake lights, tones) on…

Physics teachers have long employed video clips to study moving objects in their classrooms and instructional labs. A number of approaches exist, both free and commercial, for tracking the coordinates of a point using video. The main characteristics of the method described in this paper are: it is simple to use; coordinates can be tracked using…

This article provides a conceptualization of physical impairment as an object loss comparable to the loss of a loved one. It exists when, for example, a person has only one limb, or an illness in an organ of the body. Parkinson's disease is just such an impairment that denies the author the ability to utilize his body's previous capacity of…

Our school has a very small budget for equipment. So finding a gem like a conservation of momentum lab requiring only basic materials ("TPT", October 2005) adds a great deal to my physics course. In this lab, a "shooter" nickel makes a non-head-on collision with a stationary "target" nickel. Students measure the distance each nickel slides after…

Objects in motion attract children. The following activity helps children explore the motion of bodies riding in a vehicle and safely demonstrates the answer to their questions, "Why do I need a seatbelt?" Children will enjoy moving the cup around, even if all they "see" is a cup rather than understanding it represents a car. They will understand…

Students of all ages are fascinated by the ups, downs, loops, and twists of roller coaster rides! What they may not realize is that there is a lot of science involved in making a roller coaster work. This month's column puts students in the shoes of a roller coaster designer as they work in teams to create their own roller coasters. (Contains 1…

Our motor and perceptual representations of actions seem to be intimately linked and the human mirror neuron system (MNS) has been proposed as the mediator. In two experiments, we presented biological or non-biological movement stimuli that were either congruent or incongruent to a required response prompted by a tone. When the tone occurred with…

Two studies investigated the role of locomotor experience on visual proprioception in 8-month-old infants. "Visual proprioception" refers to the sense of self-motion induced in a static person by patterns of optic flow. A moving room apparatus permitted displacement of an entire enclosure (except for the floor) or the side walls and…

Three experiments investigated 5- through 8-month-olds' ability to encode self-propelled and caused motion and examined whether processing of motion onset changes when crawling begins. Infants were habituated (Experiments 1 and 2) or familiarized (Experiment 3) with simple causal and noncausal launching events. They then viewed the caused-to-move…

The motion of two bodies, along a straight line, under the inverse square law of gravity is considered in detail, progressing from simpler cases to more complex ones: (1) one body fixed and one free; (2) both bodies free and identical mass; (3) both bodies free and different masses; and (4) the inclusion of electrostatic forces for both bodies'…

We propose an "ab initio" introduction to the well-known Minnaert pulsating bubble at graduate level. After a brief recall of the standard stuff, we begin with a detailed discussion of the radial movements of an air bubble in water. This discussion is managed from an acoustic point of view, and using the Lagrangian rather than the Eulerian…

We describe the results of an experiment conducted to test predictions about student responses to questions about motion based on an explicit model of student thinking in terms of the cuing of a variety of different physical intuitions or conceptual resources. This particular model allows us to account for observed variations in patterns of…