Chapter 5, Problem 5.101P

To enable cooking a wider range of foods in microwave ovens, thin, metallic packaging materials have been developed that will readily absorb microwave energy. As the packaging material is heated by the microwaves, conduction simultaneously occurs from the hot packaging material to the cold food. Consider the spherical piece of frozen ground beef of Problem 5.33 that is now wrapped in the thin microwave-absorbing packaging material. Determine the time needed for the beef that is immediately adjacent to the packaging material to reach $T=0°\text{C}$ if $50\%$ of the oven power $\left(P=1\text{kW}\text{total}\right)$ is absorbed in the packaging material.