Question

Explain determination of dimensions of a physical quantity

Answer 1

The dimension of the units of a derived physical quantity may be defined as the number of times the fundamental units of mass, length and time appear in the physical quantityWe need some suitable mathematical notation to calculate with dimensions like length, mass, time, and so forth. The dimension of length is written as [L], the dimension of mass as [M], the dimension of time as [T], and the dimension of temperature as [Θ] (the dimensions of the other base units are simply omitted as we do not make much use of them in this text). The dimension of a derived unit like velocity, which is distance (length) divided by time, then becomes [LT−1] in this notation. The dimension of force, another derived unit, is the same as the dimension of mass times acceleration, and hence the dimension of force is [MLT−2].