Steam at a pressure of 7 bar and 0.95 dry is supplied to a heater through a pipe of \(25 \mathrm{~mm}\) internal diameter. The velocity of steam in the pipe is \(12 \mathrm{~m} / \mathrm{s}\). Water enters the heater at \(20^{\circ} \mathrm{C}\). The steam is blown into it and the mixture leaves the heater at \(90^{\circ} \mathrm{C}\). Calculate

(a) the mass of steam entering the heater per hour, and \((b)\) the mass of water entering the heater per hour.