Chapter 4, Problem 180P

A large chunk of tissue at 35°C with a thermal diffusivity of $\text{1 }\times {\text{ 10}}^{\text{-7}}{\text{m}}^{\text{2}}\text{/s}$ is dropped into iced water. The water is well-stirred so that the surface temperature of the tissue drops to 0°C at time zero and remains at 0°C at all times. The temperature of the tissue after 4 mm at a depth of 1 cm is

(a) 5°C

(b) 30°C

(c) 25°C

(d) 20°C

(e) 10°C