Dimensions
When a derived
quantity is expressed in terms of fundamental quantities, it is written as a
product of different powers of the fundamental quantities. The powers to which
fundamental quantities must be raised in order to express the given physical
quantity are called its dimensions.
Here the
physical quantity that is expressed in terms of the basic quantities is
enclosed in square brackets to indicate that the equation is among the
dimensions and not among the magnitudes.
Thus equation
(i) can be written as [force] = [MLT2].
Such an
expression for a physical quantity in terms of the fundamental quantities is
called the dimensional equation. If we consider only the R.H.S. of the
equation, the expression is termed as dimensional formula.
Thus,
dimensional formula for force is [MLT–2].
