ABSTRACT
A quantifiable property is generally known as a quantity. A quantity could be intensive or extensive. An intensive quantity is not dependent on the extent of the system, whereas an extensive quantity is. A quantity that appears in a mathematical application of science or engineering is known as a physical quantity. Thus, a physical quantity can be measured and expressed in numbers, and has a unit (Scott, 2000). A particular physical quantity used to compare other similar physical quantities is known as a unit. In general, the numerical value of a particular quantity depends on its unit (https://physics.nist.gov/cuu/ units/index.html). For example, among the 48 states in the continental United States, Mt. Whitney in California has the highest peak elevation of 4,418 m (or 14,495 ft) above mean sea level. Mount Everest has a peak elevation of 8,848 m (or 29,029 ft) above mean sea level. Did you notice how numerical values for the same quantity change with its units in these two examples? Did you notice, however, that the conversion factor from one unit to another stays the same and is independent of the actual values in different units? Specification of standard measurement units or dimensions and the conversion among different types of units is essential for almost every field of engineering, soil science, medical science, aviation, agriculture, commerce, industry, etc.
