A building’s fire-suppression system receives water through a vertical supply pipe of…
PHYSICS · Multi-part · CBSE · Physics · Mechanical Properties of Fluids · Mechanical Properties of Fluids
Problem
A building’s fire-suppression system receives water through a vertical supply pipe of cross-sectional area 3.0×10−3m2. The supply pipe feeds three identical risers, each with a cross-sectional area of 1.0×10−3m2. At a particular instant the water entering the supply pipe moves upward at 2.5ms−1, and the flow divides equally among the risers. Assume the water’s density is 1.0×103kgm−3 and the flow remains steady unless stated otherwise.
(a) Calculate the volume flow rate of water entering the supply pipe.
(b) Determine the average speed of the water in each riser while all three risers are open.
(c) A test of the system lasts 12min. Compute the total volume of water, in gallons, delivered by the three risers during the test. (Use 1gal=3.785L.)
(d) Partway through a second test, one riser is shut off exactly 3.0min after the test begins, while the other two continue to operate under the same conditions. Determine how much additional time beyond the original 12min would be required for the two remaining risers to deliver the same total volume of water you calculated in part (c). Show all reasoning clearly.