Why does human body heat loss increase dramatically when immersed in cold water (Hard) compared to cold air of the same temperature?
Answer and explanation
Correct answer: C. Thermal conductivity of water is approximately 24 times higher than that of still air
- Step 1: Rate of conductive heat transfer is proportional to thermal conductivity k (dQ/dt = k A Delta T / d). Step 2. The thermal conductivity of liquid water (~0.6 W/m K) is roughly 24 times greater than air (~0.025 W/m K), causing rapid hypothermia in cold water. Answer: Thermal conductivity of water is approximately 24 times higher than that of still air. Why not the others: Water has much higher specific heat capacity than air; vasoconstriction is a physiological defense; water absorbs infrared radiation.
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