The hot-water needs of a household are met by a 75-L electric water heater whose heaters are rated at 1.6 KW. The hot water tank is initially full with cold water at 20C at a rate of .078kg/s. After a shower period of 12 min, the water temperature in the tank is measured to drop to 49C. The heater remained on during the shower and hot water withdrawn from the tank is replaced by cold water at the same flow rate. Determine the mass flow rate of hot water withdrawn from the tank during the shower and the average temperature of mixed water used for the shower.....