In a meat processing plant, 4 cm-diameter spherical meat balls (k=0.45 W/m-K and =0.9110-7 m/s) that are initially at 25 C are to be cooled by passing them through a refrigeration room at -10 C. The heat transfer coefficient in the cold room is 22.5 W/m-K. If surface of the meat balls is to be cooled to 3 C, determine how long the meat balls should be kept in the refrigeration room. What will be the center temperature of the