Units and unit conversions

Dimensional analysis is a useful technique for organizing information in computations. By using this technique of canceling units and unit conversion, you can decrease your chances of making careless errors and can improve your score. 

At the end of 2004, the proved reserves of natural gas were 179.53 trillion (lO ) cubic meters (m ). [Please refer to the appendix on units and unit conversions—in this writing we use the American and British definitions of billion (10 ) and trillion (10 ), which should not be confused with the European definitions, 10 and 10, respectively. Also, unless noted otherwise, the volumetric amoimts are expressed in terms of standard m, or scm, measured at 15°C and 1 atm or 1013mbar]. In Table 1 the change in reserves over the past 20 years is illustrated ... 

While a nice solution to units issues would be to use SI units for everything (see Table A. 1 for the list of base SI units and common derived SI units), such units are not always convenient. In this textbook, a concerted effort has been made to use metric rather than imperial units for mass and length, so at least we do not have to deal with imperial-to-metric conversions. Nevertheless, we will always run into situations where other unit conversions are required. The goal of this section is to review the most common units and unit conversion we will likely be confronted with in the treatment of materials kinetics. 

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