Discusses the correctness of the directions of acceleration at various points in a pendulum problem shown in Reif (1987). Provides the author's responses to the comments on the problem. (YP)

The first demonstration shows rolling balls on two tracks: one is straight and the other dips down and then comes back up. Discusses the reason why the former is slower than the latter. The second demonstration shows a rising cork inside a water tube flowing downward. (YP)

Describes the activities of the Physics Teachers Action Research Group in which college physics teachers work together in planning, revising, and evaluating student projects that foster greater conceptual understanding and address student misconceptions. Presents the details of a project in which students were asked to build an accelerometer. (JRH)

Describes the Packard's Falling Body Apparatus, invented by John C. Packard, which is essentially an inclined plane combined with a simple and elegant method of measuring the relative time of descent of a steel ball. (JRH)

Discusses the behavior of objects in fluids having densities that increase with depth. Provides equations and a diagram of the system providing the temperature gradient. (MVL)

Discusses an aligner that permits dropping a stack of any number of balls of different sizes, elasticities, hardnesses, or types to observe the rebound of the top ball. Experimental results allow a reasonable comparison with theory. (MVL)

Two ways to visually enhance the concept of space curvature are described. Viewing space curvature as a meterstick contraction and the heavy banana "paradox" are discussed. The meterstick contraction is mathematically explained. (KR)

Six articles discuss the work of Michael Faraday, a chemist whose work revolutionized physics and led directly to both classical field and relativity theory. The scientist as a young man, the electromagnetic experiments of Faraday, his search for the gravelectric effect, his work on optical glass, his laboratory notebooks, and his creative use of…

These proceedings contain the papers of the 18th International Conference on Cognition and Exploratory Learning in the Digital Age (CELDA 2021), held virtually, due to an exceptional situation caused by the COVID-19 pandemic, from October 13-15, 2021, and organized by the International Association for Development of the Information Society…

The federal "No Child Left Behind Act of 2001" (NCLB) legislation required school districts to ensure that all teachers of core academic subjects met the requirements to be designated highly qualified by July 1, 2006. However, because no Maryland counties were able to comply with the 100 percent highly qualified designation by July 1,…

While the great scientists of the past recognized a need for a multidisciplinary approach, today's schools often treat math and science as subjects separate from the rest. This not only creates a disinterest among students, but also a potential learning gap once students reach college and then graduate into the workforce. "Cases on…

The final installment of the author's recollections of his work with physicists Enrico Fermi, Leo Szilard and others in developing the first controlled nuclear chain reaction and in preparing the test explosion of the first atomic bomb. (GS)

Described is an activity conducted to determine if Galileo could obtain the results he stated he obtained in one of his classical experiments to confirm his law of fall. (RH)

Develops a theory of gravitation which is a natural extension of the Newtonian theory. It is compatible with special relativity and with all present-day observations. It requires only elementary mathematics and can be taught in a junior level mechanics course. (Author/MLH)

Describes thermonuclear processes induced by interaction of a laser beam with the surface of a fuel pellet. An expanding plasma is formed which results in compression of the element. Laser and reactor technology are discussed. Pictures and diagrams are included. (GH)