Unit and Dimensions
2.0 Physical quantity
2.0 Physical quantity
The quantities which can be defined and measured are called as physical quantities.
Example: Distance, time, velocity etc.
Measurement of a physical quantity is a method of comparison of an unknown quantity with a standard quantity.
The measure of a physical quantity is expressed as two parts.
1. The first part gives how many times the standard unit.
2. The second part gives the name of the unit.
Mathematically,
Measurement of a physical quantity $=$ Numerical value $(n) \ \times$ unit $(u)$
Example:
- Mass of body is $1.2\ kg$
It means $1.2$ times the standard unit and the unit name is $kg$.
- Distance of $2\ km$
It means $2$ times the standard unit and the unit name is $km$.
Types of physical quantities
Physical quantities are of two types,
1. Fundamental quantities
2. Derived quantities
