What are Dimensions ?

 Each base quantity is considered a dimension denoted by a specific symbol written within square brackets. 

It stands for the qualitative nature of the physical quantity. For example, different quantities such as length, breadth, diameter, light year which are measured in metre denote the same dimension and has the dimension of length [L]. Similarly the mass and time dimensions are denoted by [M] and [T ] respectively. 

Other quantities that we measure have dimension which are combinations of these dimensions. For example. speed is measured in meter per second. This will obviously have the dimensions of length divided by time. Hence we can write ✍️

Dimensions of speed = [L]/[T]

Similarly  the dimensions of acceleration are = [L]/[T2]

And that of force = [M][L]/[T2]

Using the method of dimensions called the dimensional analysis we can check the correctness of a given formula for an equation and can also derive it.