Air is conveyed in a duct of section 300x400mm. A series of readings of velocity pressure are obtained with the aid of a Pitot static tube and a calibrated manometer. The mean value is determined as 65Pa. Determine the mean air velocity in the duct and the volume flow rate.

Data: temperature of flowing air 35C, barometric pressure 748mm mercury, density of mercury 13600kg/m3.

thanks in advance