Rocket propulsion is often introduced as an example of Newton's third law. The rocket exerts a force on the exhaust gas being ejected; the gas exerts an equal and opposite force--the thrust--on the rocket. Equivalently, in the absence of a net external force, the total momentum of the system, rocket plus ejected gas, remains constant. The law of…

Pacific Lutheran University (Tacoma, WA) is renowned for the number of its courses that offer international and study-away opportunities. Inspired by the theme of sustainability, and my growing concern about the environmental impact of conventional fuels, I offered a course, Physics of Energy, for the first time during PLU's January 2011 term (a…

Photographs of snow covered buildings are used to illustrate thermal radiation from various types of structures and the effect of insulation on heat loss. (CP)