Problem Set 5. Due Oct7. 5-1 Superheated steam can be cooled by injecting liquid water into it, and this process is termed "desuperheating." A flow of 0.5 kg/s superheated steam at 5 MPa, 400C and a flow of liquid water at 5 MPa, 40C are mixed. If saturated water vapor at 4.5 MPa is desired, what is the required flow rate of liquid water (kg/s)? 5-2 An air compressor takes in air at 100kPa, 17C and delivers it at 1 MPa, 600K to a constant pressure cooler which it exits at 300K. Find the work performed and heat transfer, both (kJ/kg). Use variable specific heats (Table A-17). 5-3 Helium (initially at 160F and 30 psia) is slowly withdrawn from a well-insulated rigid tank of volume 7 ft until the pressure reaches 18 psia. An electrical resistor inside the tank maintains the temperature at 160F. Determine the mass of helium withdrawn (lbm) and the heat input to the resistor (Btu). Note that the problem can be worked without explicitly using values for enthalpy and internal energy. 5-4 Saturated vapor steam at 4 MPa is contained in a 2 m insulated vessel. A valve on the top of the tank is opened, allowing steam to escape. If any liquid is formed, it will drop to the bottom of the tank, so that saturated vapor only will escape from the top of the tank. Calculate the total mass that has escaped when the tank pressure reaches 1 MPa. Note that value of the saturated vapor enthalpy leaving the tank changes as the pressure drops. However, the values of hg at 4 MPa and 1 MPa are not grossly different, so the average of the two can be used for the escaping stream term in the energy balance, if needed.