4–48 In a meat processing plant, 2-cm-thick steaks (k 5 0.45 W/m·K and a 5 0.91 3 1027 m2 /s) that are initially at 25°C are to be cooled by passing them through a refrigeration room at 211°C. The heat transfer coefficient on both sides of the steaks is 9 W/m2 ·K. If both surfaces of the steaks are to be cooled to 2°C, determine how long the steaks should be kept in the refrigeration room. Solve this problem using analytical one-term approximation method (not the Heisler charts).