 Physical quantities such as length [L], mass [M], time [T], and temperature are dimensional quantities and the magnitude of each quantity can be described by multiples of the unit of each dimension namely m, kg, s, and K, respectively.Through experience, we can select a certain number of fundamental dimensions, such as those mentioned above, and express all other dimensional quantities in terms of products of powers of these fundamental dimensions.Furthermore, in describing the behavior of physical processes, we know that there is an implicit principle that we cannot add or subtract physical quantities of different dimensions.