<P> A physical quantity is a physical property of a phenomenon , body , or substance , that can be quantified by measurement or we can say that quantities which we come across during our scientific studies are called as the physical quantities . A physical quantity can be expressed as the combination of a magnitude expressed by a number -- usually a real number -- and a unit : n u ( \ textstyle nu ) where n ( \ textstyle n ) is the magnitude and u ( \ textstyle u ) is the unit . For example , 6973167492749999999 ♠ 1.674 9275 × 10 kg ( the mass of the neutron ) , or 7008299792458000000 ♠ 299 792 458 metres per second ( the speed of light ) . The same physical quantity x ( \ textstyle x ) can be represented equivalently in many unit systems , i.e. x = n 1 u 1 = n 2 u 2 ( \ textstyle x = n_ ( 1 ) u_ ( 1 ) = n_ ( 2 ) u_ ( 2 ) ) . </P>
<P> A physical quantity is a physical property of a phenomenon , body , or substance , that can be quantified by measurement or we can say that quantities which we come across during our scientific studies are called as the physical quantities . A physical quantity can be expressed as the combination of a magnitude expressed by a number -- usually a real number -- and a unit : n u ( \ textstyle nu ) where n ( \ textstyle n ) is the magnitude and u ( \ textstyle u ) is the unit . For example , 6973167492749999999 ♠ 1.674 9275 × 10 kg ( the mass of the neutron ) , or 7008299792458000000 ♠ 299 792 458 metres per second ( the speed of light ) . The same physical quantity x ( \ textstyle x ) can be represented equivalently in many unit systems , i.e. x = n 1 u 1 = n 2 u 2 ( \ textstyle x = n_ ( 1 ) u_ ( 1 ) = n_ ( 2 ) u_ ( 2 ) ) . </P>
numerical value of magnitude of a physical quantity is
numerical value of magnitude of a physical quantity is
usually a real number
usually a real number