SI Unit Conversion Table pdf

The International System of Units

The General Conference on Weights and Measures, at meetings during the period 1954 - 1971, selected as base units the seven quantities displayed in table 1. This is the basis of the International System of Units, abbreviated SI from the French Le System International d Units and si unit conversion table pdf is below.

Throughout the book we give many examples of SI derived units, such as speed, force and electric resistance, that follow from table 1. Fore example, the SI unit of force, called the newton (abbreviation N), is defined in terms of the SI base units as.

1N=1kg m/S²

Table 1  SI Base Units

If we express physical properties such as the output of a power plant or the time interval between two nuclear events in SI units, we often find very large or very small numbers. For convenience, the General Conference on Weights and Measures, at meetings during the period 1960 - 1975, recommended the prefixes shown in table 2. Thus we can write the output of a typical electrical power plant, 1.3×10⁹ watts, as 1.3 gigawatts or 1.3 GW. Similarly, we can write time interval of the size often encountered in nuclear physics, 2.35 ×10^-9 seconds, as 2.35 nanoseconds or 2.35 ns. Prefixes for factors greater than unity have Greek roots and those for factors less than unity have Latin roots (except femto and atto, which have Danish roots).

To fortify table 1 we need seven sets of operational procedures that tell us how to produce the seven SI base and mass in the next three sections.

Two other major systems of units compete with the International System (SI). One is the Gaussian system, in terms of which much of the literature of physics is expressed. We do not use this system in this book. Appendix G gives conversion factors to SI units.

The second is the British system, still in daily use in the United States. The basic units, in mechanics, are length (the foot), force (the pound) and time (the second). Again Appendix G gives conversion factors to SI Units. We use SI units but we sometimes give the British equivalents, to help those who are unaccustomed to SI units to acquire more familiarity with them. In only three countries {Myanmar (Burma), Liberia and the United States} is a system other than SI used as the accepted national standard of measurement.

Table 2 SI Prefixes

In all cases, the first syllable is accented, as in na'-no-me'-ter. 

Solution

(a) For our conversion factors, we need (see Appendix G) 1 mi = 1609 m (so that 1 = 1609 m/1 mi) and 1 h= 3600s (so 1 = 1h/3600s). Thus

(b) One fluid gallon is 231 cubic inches and 1 in = 2.54cm.

Thus

Note in these two calculations how the unit conversion factors are inserted so that the unwanted units appear in one numerator and one denominator and thus cancel.