What is dimensional analysis and how is it used?

When one is faced with a problem requiring derivation of an equation, they might be asked to use dimensional analysis. This is a concept that involves analyzing the units of known quantities (usually it is easy to work in SI, one could work out these base quantities like mass in kg, distance in m, time in s, etc. by using more basic known equations) using the fact that any physically meaningful equation has the same dimensions (units, factors) on the left and the right side. 

CI

Related Physics A Level answers

All answers ▸

Describe how the average density of matter in the universe affects its ultimate fate?


A box initially at rest is on a plank, of length 5m, that is elevated at an angle such that tan(a)=3/4. When it reaches the end of the plank it has velocity 5ms^-1. Calculate the average frictional force on the box.


Electrons moving in a beam have the same de Broglie wavelength as protons in a separate beam moving at a speed of 2.8 × 10^4 m/s . What is the speed of the electrons?


Derive an expression for the time taken, (t) for a test mass to fall to the ground from a height (h) in a uniform gravitational field (g = 9.81 ms^-2)