This final article in the series on the fine-beam cathode-ray tube presents: (1) additional investigations; (2) an alternative method for the electron e/m and synchrotron radiation; and (3) two challenges to students (in a dialogue format) together with a lengthy discussion on synchrotron radiation sources. (DH)

In 1935 physicist Hideki Yukawa proposed the meson theory of nuclear forces. Background, influences, and chronology of Yukawa's work are presented and discussed. Yukawa was supported in his meson idea by Japan's strong emphasis on intuitive and creative approaches which are also evident in subsequent developments in that country. (DH)

Measurement of the brightness of moonlight by comparison with lamp-light from a low wattage light bulb is an elementary project in astronomy which illustrates scientific principles for the freshman level. Two methods used for the comparison (shadow brightness method and grease spot method) are explained, with suggestions and expected answers. (DH)

Presents a technique which aids students in solving static problems involving three or more torques about a given axis. The method is longer and equivalent to the standard method, but students experience success with this new way to treat the more complicated equilibrium problems. (DH)

Shows how an electric stud finder (available from hardware stores for $15-20) is used to detect changes in capacitance produced by changes in thickness of a medium or in dielectric constant. Also describes how to construct an inexpensive motor from a battery, rubber bands, ceramic magnet, and copper wire. (DH)

Explains the effect that depth of water has on the speed of Olympic-style racing canoes and kayaks. Indicates that canoes are harder to paddle in shallow water because the skin friction drag increases appreciable when the water depth decreases. (DH)

Describes these tools for physics teaching: (1) stick with calibrations for measuring student reaction time; (2) compact high-pressure sodium lamps used to demonstrate spectra; (3) air pumps for fish tanks providing simple inexpensive motors; (4) a rotating manometer for measuring centripetal force; and (5) an apparatus for checking conservation…

Suggests a way to change the role of physics teacher. Discusses the teacher as a coach, reducing anxiety, team cooperation, and a grading system including "forgiving learning" which recognizes student's progress. (YP)

Presents examples to show the ubiquitous nature of geometry. Illustrates the relationship between the perimeter and area of two-dimensional objects and between the area and volume of three-dimensional objects. Provides examples of distribution systems, optimum shapes, structural strength, biological heat engines, man's size, and reflection and…

Introduces an experiment exhibiting blue and yellow-orange coloration in the plane of vibration of a vibrating string. Provides pictures and the experimental set-up. (YP)

Describes experiences with turtle graphics to demonstrate motion in a constant gravitational field. Provides the computer program and typical diagrams. (YP)

Discusses four different methods for measuring self-inductance based on the definition of inductance, the alternative definition, phase difference and LC resonance. Provides circuit diagrams and typical oscilloscope traces. (YP)

Introduces two hands-on experiences, related to rotational motion and moment of inertia. Discusses the experimental procedures and provides figure of apparatus. (YP)

Introduces a 3-dimensional mechanical lattice with adjustable telescoping mechanisms. Discusses the crystalline state, the 14 Bravais lattices, operational principles of the mechanical lattice, construction methods, and demonstrations in classroom. Provides lattice diagrams, schemes of the lattice, and various pictures of the lattice. (YP)

Reviews "Vernier Software: Precision Timer II" for high school through college mechanics. Introduces 14 different modes including pulse time, pendulum timer, bouncer timer, gate timer, collision timers, and stroke calibration. Provides two typical displays and ratings of the software. (YP)