$4\mathrm{.}6\mathrm{.}22$ Figure P$4\mathrm{.}6\mathrm{.}22$ shows a duct for testing a centrifugal fan. Air is drawn from the atmosphere $(($:$p_{\text{a}\text{t}\text{m}}=101\mathrm{.}3$kPa,$T_{\text{a}\text{t}\text{m}}=21\mathrm{.}1C\}.$ The inlet box is $1\mathrm{.}2m0\mathrm{.}6m.$ At section $1,$ the duct is square in cross$-$section $(0\mathrm{.}76m0\mathrm{.}76m).$ At section $2,$ the duct is circular and has a diameter of $0\mathrm{.}9$ m $.$ A water manometer in the inlet box measures a static pressure of $-0\mathrm{.}05$ m of water. Calculate the volume flowrate of air into the fan and the average fluid velocity at both sections $1$ and $2.$ Assume constant density.