The answers from test questions on circular motion are analyzed in terms of the misunderstandings of resultant force, kinematics, interaction, and centrifugal force. (DS)

Shows how the thermal power developed by friction is exactly half the supplied power in the general case of a variable force of friction. Investigates the mechanism whereby one-half the input energy is dissipated as heat using mathematical expressions. (YP)

Explains the physics behind some of the apparently puzzling aspects of the motion of a person riding a snake-board (a skateboard with independently pivoted axles). (Author/WRM)

Calculates the angular velocity of a spinning top without the simplifying assumption found in most textbooks that the total angular momentum is solely along the symmetry axis. (WRM)

Describes how Newton's three laws of dynamics are taught in high school in the Soviet Union. Rejects introducing Newton's second law as an equation defining mass as a proportionality constant. Shows how the concept of mass can be introduced independently of Newton's Law. (GA)

Describes an introductory physics experiment concerned with scattering particles off various force centers. The experiment uses simulation techniques and a computer. The scattering is classical, and the student examines plots of computed particle trajectories. The results illustrate the concepts of differential corss-section, total cross-section,…

An investigation was conducted of the relative drag experienced by different types of tea/coffee stirrers to make deductions about their stirring efficiencies. Experiments compared the stirring performances of convex and concave sides of a plastic teaspoon with the performance of a commercial stirrer. The performance of the spoon exceeded that of…

Describes an alternative set-up for demonstrating Lenz's Law in which the magnet can be seen during its fall. (WRM)

Investigated was the nature of teachers' ideas about force and gravity, changes in materials, and energy. Information was obtained by using interview-about-events and interview-about-instances techniques. Examples of teachers' conceptions and ways of thinking are included. (YP)

Discusses pupil misconceptions concerning forces. Summarizes some of Assessment of Performance Unit's findings on meaning of (1) force, (2) force and motion in one dimension and two dimensions, and (3) Newton's second law. (YP)

Investigates the nature of college student difficulties with negative values of velocity by using interviews. Discusses graphical representation of negative values of velocity and interpretations of graphs involving negative values of force. Suggests some instructional implications from the discussion. (YP)

Describes two simple demonstrations of an object moving in a straight line tangent to the circle if centripetal force is removed. Demonstrations use a pie plate and petri dish with ball bearings to illustrate the phenomena on an overhead projector. (LZ)