Newton's cradle is a well-known physics toy that is commonly used by teachers to demonstrate conservation laws in mechanics. It can also be used to investigate the physics of colliding objects, by recording motion of the balls on video film. Various experiments are described using 3-ball and 5-ball cradles, showing how different types of collision…

Leaders and citizens of the next generation will have to do more with less. There will be fewer natural resources (e.g., less timber and less biodiversity), and the world's population will be greater. As a result, education must equip the students of today with the skills they need to cope with change, uncertainty, and complexity. This type…

This article describes some aspects of Piaget's Theory of Cognitive Development. It highlights the importance of giving young children specific access to explore conservation in measurement, which will give students invaluable experiences in measurement that in years to come will be regarded as their prior knowledge of the concept. This is…

Presents a derivation of Kepler's Third Law for elliptical orbits that requires students to have a knowledge of angular momentum and conservation of energy. (JRH)

Outlines the use of the toy popularly known as Newton's Cradle or Newton's Balls in illustrating the laws of conservation of momentum and mechanical energy. Discusses in detail the joint effects of elasticity, friction, and ball alignment on the rate of damping of this apparatus. (JRH)

Presents an experiment that demonstrates conservation of momentum and energy using a box on the ground moving backwards as it is struck by a projectile. Discusses lab calculations, setup, management, errors, and improvements. (JRH)

Discussed are the results of interviews with 63 Australian children (interviewed in English) and 62 Nigerian children (62 interviewed in English and 60 interviewed in Yoruba) to determine how they used number concepts in discussing five demonstrations manipulating physical matter. Differences between the two groups are considered. (RH)

Presents exercises that analyze the additive property of energy. Concludes that if a body has more than one component of energy depending on the same physical quantity, the body's total energy will be the algebraic sum of the components if a linear relationship exists between the energy components and that physical quantity. (JRH)

Presents a mechanical model that is able to duplicate the torque-free twist of a real cat. Discusses results of experiments that analyze its free fall from an inverted position. (JRH)

Discusses a series of experiments to establish a significance of temperature difference in rates of cooling, to illustrate the connection between energy transfer and the consequent temperature changes for thermally connected systems that are not in equilibrium. (MKR)

Applies the concepts of kinematics and conservation of mechanical energy to calculate the time needed to reach a certain point along semicircular and parabolic paths. Presents numerical calculations for the critical speed thresholds for the paths of semicircular and parabolic curves. (JRH)

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)

Investigated was the learning of the mathematical uses of "more,""fewer," and "less" at a very early stage in the development of ideas. (CW)

Describes some inexpensive activities and demonstrations that illustrate basic concepts that are often overlooked, as a low-cost means to foster student participation in physics classes. Activities described deal with acceleration and forces, freefall, conservation of energy and momentum, conservation of angular momentum, and resonance. (JRH)

Advocated is the use of everyday games and situations instead of the traditional use of textbooks, workbooks, and worksheets. New goals and principles for the beginning arithmetic student are presented. Modifications of activities that promote the constructivist ideal are included. (KR)