Calculate the pressure drop for air at $38\backslash$deg C and $1$ atm flowing at $0\mathrm{.}95$ kg$/$s through a bed of spheres of $0\mathrm{.}0127$ m diameter. The bed is $1\mathrm{.}25$ m in diameter and $2\mathrm{.}5$ m high. Consider the porosity of $0\mathrm{.}38$