Dimensional Analysis is really simple and I have read that it is only used to verify the derived equations. But I don't understand how we work with constants in Dimensional Analysis. For example, if we are given KE depends on mass and velocity, we can easily derive KE = 1/2 mv2. In the above case we assume the proportionality to be dimensionless but what do we do if we want to derive the Newtonian relation between gravity and mass/distance. Do we still assume the constant G to dimensionless and later give it dimensions to fit the other units?