A simulation exercise involving being transported to another planet forces students to use different instruments, devices, and units for measuring. (CP)

Describes an undergraduate optics laboratory experiment to verify the law of intensity in the Fesnel diffraction of a thin wire. A gas laser as light source and a photocell as detector scan the diffraction pattern. The agreement with the theoretical pattern is remarkably good. (Author/TS)

A discussion of linear collisions between two or three objects is related to a junior-level course in analytical mechanics. The theoretical discussion uses a geometrical approach that treats elastic and inelastic collisions from a unified point of view. Experiments with a linear air track are described. (Author/TS)