Three fire hoses are connected to a fire hydrant. Each hose has a radius of 0.023 m. Water enters the hydrant through an underground pipe of radius 0.077 m. In this pipe the water has a speed of 2.7 m/s.
(a) How many kilograms of water are poured onto a fire in one hour by all three hoses?
(b) Find the water speed in each hose.