If x is the distance measured from the leading edge of a

If x is the distance measured from the leading edge of a flat plate, then laminar boundary layer thickness varies as

ρ =	5x	for laminar flow
	√Re

Re_x =	Vx
	υ

∴ ρ =	5√x	for laminar flow
	√V / υ

∴ ρ ∝ √x