Question

An oil with a viscosity of $\mu$ and density $\rho$ flows in a pipe of diameter $D$. The pressure drop $\Delta P$ needed to produce a flow rate of $Q$ for laminar flow is given as

$\Delta P=k\frac{Q\mu L}{D^4},L$ is length of pipe

The value of $k$ is _____.

• A. 40.74

Answer 1

The correct option is A 40.74
$\Delta P=\frac{128\mu LQ}{\pi D^4}=k\frac{\mu LQ}{D^4}$

$k=\frac{128}{\pi }=40.74$