A bare-footed person whose feet are at 32°C steps on a large aluminum block at 20°C. Treating both the feet and the aluminum block as semi-infinite solids, determine the contact surface temperature. What would your answer be if the person stepped on a wood block instead? At room temperature, the √k_ρc_p value is 24 kJ/m²·°C for aluminum, 0.38 kJ/m²·°C for wood, and 1.1 kJ/m²·°C for human flesh.