Presents a variety of problems, involving kinematics and dynamics, that deal with ropes and their centers of mass. (JRH)

Provides an explanation of how tubeless tires support the weight of an automobile with reference to the use of free body diagrams in physics. Presents a second activity in which an inexpensive laser pointer is used to obtain diffraction photographs. Offers project ideas for students. (ZWH)

Provides a laboratory experiment using a pendulum on the conservation of energy. The activity has an easy analysis, accurate results, and is enjoyable for the students. (MVL)

States that the terms hydrostatic pressure, static pressure, dynamic pressure, and impact pressure are poorly named and suggests new names to better explain the physical properties. (MVL)

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)

Illustrates a direct method for estimating the energy loss due to air drag on the pendulum bob and cord, starting from basic principles and using standard drag coefficients. Also shows how to hang the pendulum in a way to make it easy to evaluate the frictional losses at the support. (MVL)

Provides a particle-in-a-box model to help students understand and estimate the magnitude of the characteristic energy scales of a number of quantum systems. Also discusses the mathematics involved with general computations. (MVL)

Provides a group activity concerning loading conditions and vectors in equilibrium. Uses a cardboard template, string, and one-kilogram masses. Includes some possible resulting vector diagrams. (MVL)

The effects of temperature and pressure on the collapsing of soda cans are discussed. The use of various temperatures and substances for the cooling bath are described. (KR)

The term "microgravity" has begun to appear in science texts as a substitute for "weightlessness." Presents examples to clarify three common misconceptions about gravity and weightlessness. Further examines these and other examples with respect to microgravity to make distinctions between the terms and avoid additional…

Discusses the physics of the "Ollie," a skateboard jump in which the skateboarder does not hold on to the board. The motion is described through three graphs that illustrate the positions of the tail of the skateboard, the center of mass, and the nose of the skateboard during a jump. (MDH)

A static method of measuring the surface tension of a liquid is presented. Jaeger's method is modified by replacing the pressure source with a variable pressure head. By using this method, stationary air bubbles are obtained thus resulting in controllable external parameters. (Author/KR)

Provides 32 free-body diagrams. Students are to draw all forces acting on the rock in the diagrams. Gives an example. (MVL)