A mountain climber wears a goose-down jacket 3.5 cm thick with total surface area 0.95 m2. The

Question:

A mountain climber wears a goose-down jacket 3.5 cm thick with total surface area 0.95 m2. The temperature at the surface of the clothing is and at the skin is 34°C. Determine the rate of heat flow by conduction through the jacket assuming
(a) It is dry and the thermal conductivity k is that of goose down,
(b) The jacket is wet, so k is that of water and the jacket has matted to 0.50 cm thickness.