An aluminum tray used for making ice cubes is filled with water and placed in a freezer at -19.8° C. The emissivity of the aluminum is close to zero, but the emissivity of water or ice is 0.950. The exposed top surface area of each ice cube is 20.8 cm2.
(a) Find the rate at which heat is removed from an ice cube by radiation just as the water begins to freeze.
(b) How long would it take for radiation alone to remove enough heat to freeze the ice cubes if each has a mass of 75.2 g?