Given the relation,
Dimension of m = M1 L0 T0
Dimension of mo = M1 L0 T0
Dimension of v = M0 L1 T–1
Dimension of v2 = M0 L2 T–2
Dimension of c = M0 L1 T–1
The given formula will be dimensionally correct only when the dimension of L.H.S is the same as that of R.H.S.
This is possible when the factor in the denominator is dimensionless. This is only possible if
Hence the correct relation is
Define physical quantity.
The quantity used as a standard of measurement is called unit.
Example: Unit of time is second.