Teaching cosmology at the undergraduate or high school level requires simplifications and analogies, and inevitably brings the teacher into contact with at least one of the pedagogical interpretations of the expanding Universe. The by far most popular interpretation holds that galaxies in an expanding Universe are stationary, while space itself…

Newton's second law is one of the cornerstones of the introductory physics curriculum, but it can still trouble a large number of students well after its introduction, hobbling their ability to apply the concept to problem solving and to related concepts, such as momentum, circular motion, and orbits. While there are several possibilities for…

Elementary, middle-level, and high school science teachers commonly find their students have misconceptions about heat and temperature. Unfortunately, student misconceptions are difficult to modify or change and can prevent students from learning the accurate scientific explanation. In order to improve our students' understanding of heat and…

An interesting, quick, and inexpensive lab that we do with our students is to tape one end of a string just less than halfway around the back side of a uniform solid cylinder m[subscript 1] and attach the other end of the string to a mass m[subscript 2] that is below a pulley (Fig. 1). Data can be collected using either an Ultra Pulley (Fig. 2) or…

Describes an activity with cars and fans that observes the motion of cars under force. Lists required materials, the procedure, and introductory questions for the activity. (YDS)

Presents an exercise that attempts to correct for the common discrepancies between theoretical and experimental predictions concerning projectile motion using a spring-loaded projectile ball launcher. Includes common correction factors for student use. (MVL)

A mechanical analogy between the microscopic motion of a charged carrier in an ordinary resistor and the macroscopic motion of a ball falling along a slanted board covered with a lattice of nails is introduced. The Drude model is also introduced to include the case of inelastic collisions. Computer simulation of the motion is described. (KR)

Described are the results of interviews of students regarding the concepts of "forced" and "natural" motion. Aristolean-like beliefs have been found to persist in students even though these views differ from orthodox physics views. (KR)

Explains reasons why students have misconceptions concerning pendulum swings. Presents a series of 10 pendulum task cards to provide middle-school students with a solid mental scaffolding upon which to build their knowledge of kinetic energy and pendulums. (PR)

Presents a first day physics activity having students determine the fine for a speeding ticket if the speeds considered include the earth's rotation and revolution speed, and the movement through the galaxy. (MDH)

Students lacking formal training in physics have great difficulty predicting the paths of various projectiles. With respect to pendulum-bobs that are released from various points in a swing, a previous experiment found that empirical feedback (i.e., resultant trajectories) produced transfer-of-training to other pendular-based tasks. However, such…

Reports on an attempt to bring about conceptual change in children's concept of speed by the teaching of the science of speed emphasizing an integrated hands-on experience. Reports that it may be possible to modify naive conceptions by teaching that targets particular concepts. (Author/YP)