Physical Quantities:

All measurable quantities are called physical quantities such as length, mass, time, and temperature.

A physical quantity possesses at least two characteristics in common. One is its numerical magnitude and the other is the unit in which it is measured.

Examples:

For example, if the length of a student is 104 cm then 104 is its numerical magnitude and a centimeter is the unit of measurement.

Similarly, when a grocer says that each bag contains 5 kg of sugar, he is describing its numerical magnitude as well as the unit of measurement. It would be meaningless to state 5 or kg only.

Physical quantities are divided into base quantities and derived quantities.