Physical Quantities

Measurement

Physical quantities are those which can be measured directly or indirectly regarding their quality as well as quantity. For example, mass is the physical quantity as it can be measured directly or indirectly by using a beam balance or a pan balance; length can be measured by using scale, meter scale or measuring tape; time by using clock or watch and so on. Similarly, area and volume are also physical quantities as they can be measured by using formula directly or by using any other indirect methods like use of graph for measuring area and displacement method for measuring volume.

Physical quantities can be broadly categorized into two types- fundamental quantities and derived quantities. They are explained below:

1. Fundamental quantities:

Those physical quantities which do not depend upon any other physical quantity are called fundamental quantities. These are independent physical quantities and are also called basic quantities. For example, can you tell how much kilogram of mass is equal to 1 metre or 1 hour? Obviously not? It is because mass, length and time are totally independent to each other and hence they are called the fundamental quantities. 

2. Derived quantities

Those physical quantities which are dependent upon the fundamental quantitiesw are called derived quantities. These quantities are derived quantities as they are originated or derived from the basic units. These are also called dependent quantities. For example, velocity, acceleration, presure, work, densitys. 

Memory Tips: Physicval Quantity = Numerical Value×Unit