So all variables that we're interested in can, generally speaking,

be expressed in terms of those three primary dimensions,

either F L and T or M L and T depending.

For example, acceleration is LT to the minus 2.

Density is mass per unit volume ML to the minus 3, etcetera.

All are expressible in terms of the three fundamental dimensions.

Now, the next very important principle in dimensional analysis is

the Buckingham Pi Theorem, which was first formulated in 1914.

And here is the section from the reference handbook.

And the Buckingham Pi Theorem states this.

That, let's suppose we have some variable, which we'll denote by U1,

is some function of other variables U2, U3, etcetera, up to Un.

In other words, U1 is some function

of these other variables or it depends on these variables.