A proposal is made to use a geothermal supply of hot water to operate a steam turbine, as shown in Fig. P6.105. The high pressure water at 200 lbf/in.2, 350 F, is throttled into a flash evaporator chamber, which forms liquid and vapor at a lower pressure of 60 lbf/in.2. The liquid is discarded while the saturated vapor feeds the turbine and exits at 1 lbf/in.2, 90% quality. If the turbine should produce 1000 hp, find the required mass flow rate of hot geothermal water in pound-mass per hour.