Two cylindrical reservoirs A and B are connected by a 30 m long pipe of 250 mm internal diameter as shown in Figure below. The Darcy-Weisbach friction factor for the pipe is 0.025. Initially the reservoir A was full at the indicated level and reservoir B was empty. If the entrance and exit losses in this pipe are neglected, the time required to empty the reservoir A in hour is _______. (rounded off to 3 decimal places, Consider π = 3.14 and g = 9.81 m s^-2)