APPENDIX A
The International System of Units
The International System of Units(SI), uses a single basic unit
for each physical quantity, and multiples and fractions of this
unit are formed by adding a prefix. For example, the SI unit for
length is the meter (m). The millimeter (mm), centimeter (cm),
and kilometer(km) are formed by adding the prefixes milli (m),
centi (c), and kilo (k) to meter. The same prefixes are used
for all physical quantities. The prefixes and their symbols are
listed in Table A.1.
The following rules should be observed when using SI symbols of
units:
 Do not put a period after a symbol. Therefore, 7 km. is incorrect,
but 7 km is correct.
 Do not put s at the end of any symbol. Therefore, 7kms is
incorrect, but 7 km is correct.
 The symbol for a unit is a lowercase letter except when the
unit is derived from a proper name(i.e. Newton, Pascal, Joule
etc.). Thus, the symbol for the meter is m, whereas the
symbol for the Newton is N. (An exception is the symbol
for L for liter.)
 A symbol with the prefix is treated as a new unit which can
be raised to a power without using brackets. Thus, the notation
means , and not .
Table A.1 SI Prefixes
Prefix  Symbol
 Value 
tera  T 

giga  G 

mega  M 

kilo  k 

hecto  h 

deca  da 

deci  d 

centi  c 

milli  m 

micro  

nano  n 

pico  p 

femto  f 

atto  a 

Table A.2 Common SI Units
Fundamental Units
Quantity  Name of Unit
 Symbol of Unit 
Length  Meter  m

Mass  Kilogram  kg

Time  Second  s

Temperature  Kelvin  K

Electric Current  Ampere 
A 
Derived Units
Quantity  Name of Unit
 Symbol of Unit  Unit(with Fundamental Units)

Frequency  Hertz
 Hz 

Force  Newton
 N 

Pressure  Pascal
 Pa 

Energy  Joule
 J 

Power  Watt
 W 

Electric charge  Coulomb
 C 

Electric potential  Volt
 V 

Electric resistance  Ohm
 

Electric capacitance  Farad
 F  
Magnetic filed  Tesla
 T  
Magnetic flux  Weber
 W  
Table A.3 Conversion Factors
Unit  Conversion Units

1 degree 

1 revolution 

1 meter  3.281ft=39.37in.

1 light year 

1 kilogram  2.205lb=35.27oz

1 atomic mass unit 

1 slug  14.59kg 
1 cubic meter 

1 joule 
