Question

what are the limitations of dimentional analyses

Answer 1

We are unable to work with trigonometric ratios.
This method cannot be used if the physical quantity contains more than one term, say sum or difference of two terms.

time is not include ......................... 

Answer 2

Dimensional analysis has no information on dimensionless constants.If a quantity is dependent on trigonometric or exponential functions, this method cannot be used.In some cases, it is difficult to guess the factors while deriving the relation connecting two or more physical quantities.This method cannot be used in an equation containing two or more variables with same dimensions.It cannot be used if the physical quantity is dependent on more than three unknown variables.This method cannot be used if the physical quantity contains more than one term, say sum or difference of two terms.