The ideal gas law, "PV = nRT," is one of the simplest physical laws in nature that is introduced to students as early as in high school and first year in college. In this equation, "P" stands for pressure, "V" is the volume, "n" is the amount expressed in mole, "T" is the temperature in Kelvin…

Various experiments on vibrating gas columns and on frequency measurements with glasses and pipes have been presented in recent years in the "iPhysicsLabs" column. The determination of the sound velocity in different gases by measuring the sound running time has also already been proposed in an earlier paper. This article now adds…

A television advertisement and a website present an interesting question: can rail company CSX "really" move a ton of freight 468 miles on a gallon of fuel, or is the claim preposterous? Let us examine the claim, first by understanding what is meant, looking at their data, and then converting units to examine the claim quantitatively.

An athlete sitting on a bicycle seat can produce about 100 watts of useful power on a long-term basis. After 10 hours, the athlete produces 1000 watt-hours, or one kilowatt-hour (kWh). While some people balk at the notion of having to pay (say) 8.5 cents rather than their present 8 cents for that kilowatt-hour, what would they have to pay the…

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…

Early in the last century, Robert Millikan developed a precise method of determining the electric charge carried by oil droplets. Using a microscope and a small incandescent lamp, he observed the fall of charged droplets under the influence of an electric field inside a small observation chamber. In so doing, Millikan demonstrated the existence of…

It is claimed by the company NitroFill and the GetNitrogen Institute that filling car tires with nitrogen improves gas mileage considerably. The reason given is that oxygen leaks out of tires so that the increased rolling friction causes a reduced gas mileage. Because it is hard to do an actual road test, we report on a simple visual test of…

Demonstrates, using specific problems, how various energy units can be converted to joules and power units to watts. Conversion tables are provided for power, energy, generation values, thermal insulation, consumption values, sunlight, with tables also on metric prefixes and time conversions. (SK)

Presents 15 energy-related physics problems, including a brief indication of the essential features for solving each problem. Problems reflect various energy-related situations and involve different areas of physics. (SK)

Explains the operation of the Magnetohydrodynamic (MHD) generator and advantages of the system over coal, oil or nuclear powered generators. Details the development of MHD generators in the United States and Soviet Union. (CP)

Studies the practicality of water-filled flat-plate solar collectors. An estimate of solar energy gathering abilities and applications in heating of homes are considered. (CP)

Examines the relationship between climatic change and carbon dioxide from the historical perspective; details the contributions of carbon-based fuels to increasing carbon dioxide concentrations; and using global circulation models, discusses the future impact of the heavy reliance of our society on carbon-based fuels on climatic change. (BT)

Describes petroleum exploration techniques, particularly the interpretation of seismograms. (CP)

Reports on technological advancements in the fields of solar collectors, thermal storage systems, and solar heating and cooling systems. Diagrams aid in the understanding of the thermodynamics of the systems. (CP)