# Deriving Force Equation from Scaling Law

1. Feb 21, 2013

### hudzaifah

Hi.
I am reading this chapter about dimensionless ratios and scaling law. and it says like this:

$\alpha$F = $\frac{Fp}{Fm}$ = $\frac{ρp . Vp^2 . Lp^2}{ρm . Vm^2 . Lm^2}$ (1)

From this, it is obvious one can write for these forces:

Fp = C$\frac{1}{2}$ $ρp Vp^2 . Lp^2$ (2) and
Fp = C$\frac{1}{2}$ $ρm Vm^2 . Lm^2$ (3)

The thing I don't understand is, how can from equation (1) to equation (2) and (3)..