posted by Marisca .
A room measures 4.0 m by 3.9 m by 4.5 m. The heating and air-conditioning ducts to and from the room are circular with diameter 0.37 m and all the air in the room is to be exchanged every 14 min.
(a) What is the average flow rate?
(b) What is the necessary flow speed in the duct? (Assume that the density of the air is constant.)
(a) (Room volume)/(840 s) = ______ m^3/s
(b) (Flow rate)/(duct area)