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1.3.1 Measurement systems: The Metric System and Its Modification the SI system
There are many measurement systems. The top three are the cgs (centimeter, gram, second) system, mks
(meter, kilogram, and second) system, and the English (foot, slug, and second) system.
The metric system of measurement (established in 1791) or it‟s SI (System International) modernized
version (established in 1960) is the most common and widely used system by scientists worldwide. Table
(1.1) shows measurements of some basic physical quantities and their standard units in both metric and SI
units.
Table (1.1) Measurements in Metric and SI Systems
measurement
Metric (symbol)
SI (symbol)
Length
Meter (m)
Meter (m)
Mass
Gram (g)
Kilogram (kg)
Volume
Liter (L)
Cubic meter (m3)
Time
Seconds (sec)
Seconds (sec)
Temperature
Celsius ( 0C)
Kelvin (K)
In this course we will use the metric system. This system employs prefixes or powers of 10 to describe
large or small quantities. This will make it easy in writing large and/or small numbers. Table (1.2) lists
some prefixes with their abbreviation and their meaning.
Table (1.2) Some Common Prefixes