Question

The unit of density is considered as a derived unit .Give reason. shortnote​

Answer 1

Density is measured in kg⋅m−2 . This means that it is derived from fundamental units which are the kilogram and metre. The kilogram is defined as the mass of a platinum-iridium cylinder which is kept in France. This is the only fundamental unit which is still defined by an artefact.

Answer 2

UNIT OF DENSITY IS A DERIVED UNIT !

But why?

• First of all, unit of density is kg/m³, and kg/m³ is not a fundamental unit as a whole.

• Instead, kg (for mass) and metre (for length) are fundamental unit.

Using DIMENSIONAL ANALYSIS, the unit of density has been derived as follows:

$\therefore \: \rho = \dfrac{ \bigg \{mass \bigg \}}{ \bigg \{volume \bigg \}}$

$\implies \: \rho = \dfrac{ \bigg \{mass \bigg \}}{ \bigg \{ {(length)}^{3} \bigg \}}$

$\implies \: \rho = \dfrac{ kg}{ {m}^{3} }$

$\implies \: \rho = kg/ {m}^{3}$

Hence, the unit is a derived unit.