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 ▸

A ball of mass 0.7 kg strikes the wall at an angle of 90 degrees with speed 72 km/h. Consider that the bounce lasts for 0.1 s and is perfectly elastic. What is the magnitude of the average reaction force from the wall that acts on the ball?


A rock has a mass of 100g and it is thrown across a pond at a speed of 30ms^-1. Calculate the de Broglie wavelength of the rock and explain whether you can see the wave produced.


Give an example of 3 different types of radiation stating their make up, penetration and ionising effect.


Two identical uniform spheres each of radius R are placed in contact. The gravitational force between them is F. They are then separated until the force between them is one ninth of the magnitude. What is the distance between the surfaces of the spheres?