At every toilet stall on the Pt. Lisas Campus a fan is to be selected to ventilate each stall, whose dimensions are 3.82 m x 3.34 m x 4.40 m. In accordance with air requirement standards, the volume of the air in each stall must be replaced every 9 minutes. The air velocity is not to exceed v= 10.7 m/s to minimize vibration and noise. Determine 1. The mass flowrate of air to be removed from each toilet stall (kg/sec) 2. the minimum duct diameter, D, required in metres (g=9.81ms 2, 1.25kgm ?, atmospheric pressure =101kPa) Circular Metal duct Atmospheric conditions Atmospheric conditions V Fan m/s Exhaust fan Air B