A heat exchanger is used to recover waste heat from an industrial furnace and use it to heat pressurized water. The heat exchanger consists of a tube bank with a square 10 x 10 array of thin-walled smooth tubes (total of 100 tubes). The tubes are aligned in-line with a transverse pitch, ST = 50 mm. Each tube is 25 mm in diameter and 4 m long. Water passes through each tube at a flow rate of 0.025 kg s-1, so the total flow rate through all 100 tubes is 2.5 kg s-1. The exhaust gas is in cross-flow over the tubes, with an upstream velocity of 5.0 m s-1 and total flow rate of 2.25 kg s-1. The exhaust gas has properties similar to air. The inlet temperatures of the water and exhaust gas are 300 K and 800 K, respectively. (a) What is the overall heat transfer coefficient between the water and the gas? (b) What are fluid outlet temperatures? As a first approximation, assume the water flow through the tubes is fully developed and turbulent, with an estimated bulk mean temperature of 350 K. Use a mean temperature of 600 K and properties of air to represent the exhaust gases. Please comment on the accuracy of these assumptions after you obtain your results, but you do not need to repeat any calculations.