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The properties of a fluorescent lamp are explained. Topics include ac circuit analysis; plasma, which consists of ionized particles and radiation; power transfer; and implications of the economics and mechanics of power consumption.

Every aeronaut, including a man who planned to float above his backyard with 45 helium-filled weather balloons attached to a lawn chair, needs to know some physics, in which there is some survival value. In a technologically complex world it is important for everyone to know some universal laws and fundamental principles of technology. The story of the helium balloons and the lawn chair, which ended up at 11,000 feet in altitude rather than the planned 30 feet, can be useful for teaching students. Mass, displaced volume, air density/temperature and other factors go into predicting an equilibrium altitude.

Coke bottles containing different amounts of water can be used for musical purposes in an introductory physics course, but the tones cannot easily be explained. The fundamental frequency and the length of the air column have a relationship that must be determined to see musical properties of a bottle as an acoustic resonator. An organ pipe is not a useful model for predicting fundamental frequency. A rather simple approach avoids solving the differential equations of wave theory. It is made by analogy of acoustic resonator elements of ac circuit analysis. The bottle is seen as a short neck inserted into a longer tank, a Helmholtz resonator.