Symbols, Units and Prefixes

1(f) Symbols, Units and Prefixes

Physics is known as the science of Measurements. It obviously has many physical quantities.

A physical quantity is written as a numerical magnitude followed by a suitable unit. In physics , SI units i.e. the International System of units is adopted.

There are a few Base quantities and some Derived Quantities in Physics. The following are the base quantities.

Derived quantities are quantities made from a combination of the base quantities. Some examples are the following.

Area = Length (m) * Width (m)                       Units: meter(square)

Volume =Length (m) *Width(m)*Height (m)      Units: meter(cube)

Speed = Distance travelled (m) / Time taken(s)     UNITS: m/s

PREFIXES AND THEIR SYMBOLS

The other thing that should be kept in mind are Prefixes. Prefixes are placed before the SI units to give them a specific value.

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For example, a centimeter is a meter multiplied by 10. I hope you now understand what prefixes are.