Calculate the pressure drop of air flowing at $30C$ and $1$ atm pressure through a packed bed of $1\mathrm{.}25cm$ diameter spheres at a $60k\frac{g}{m}in$ rate. The bed is cylindrical in shape having $1\mathrm{.}25m$ diameter and $2\mathrm{.}5m$ height. The porosity of the bed is $0\mathrm{.}38.$ The viscosity of air is $0\mathrm{.}0182cP,$ and the air density is $0\mathrm{.}001156g\frac{m}{c}c.$