4. An auto radiator accepts engine coolant at 1 kg/s and 80C and discharges the coolant at 60C (both at 200 kPa). The coolant can be assumed to be water. Air is blown through the radiator by a fan to carry the heat away. Assume the fresh air entering the radiator is at 20C and the hot air exiting the radiator is 50C. Find the required air flow so you can tell the mechanical designer how to size the fan (kg/s). Try solving this one without Thermofluids using Ah-C-AT where for liquid water C-=4.184 kJ/kg-K and for air Cp-1.0 kJ/kg-K. Think about choosing a CV that makes this problem as simple as possible. Water out, 60C Fan pushing air in at 20C Air out, 50C Water in, 80C 5. Air enters an adiabatic nozzle at 400 K as shown. It is accelerated to a measured velocity of 200 m/s. Find the air temperature at the nozzle exit. Hints: You can use the CP expression for air from Problem 4. Also, be careful with units, as keeping KJ vs. J straight is important here. Air, 400K Air, 200 m/s * Please help me with question 5