冰同空氣邊個係較不良的傳熱體?

Q: 冰同空氣邊個係較不良的傳熱體?

Air is a poor conductor of heat, when compared with ice. The thermal conductivity of air (at 0'C) is 0.024 W/m-K, but that of ice (at 0'C) is 2.2 W/m-K. It is thus clear that ice conducts heat almost 100 times better than air.


Q:佢提出的第2點咪唔成立？


The saying is not wrong. It is correct.

When water on the fruit surface freezes and turns into ice, the temperature of the fruit surface remains at 0'C. It is because there is no temperature change during a change of state from water to ice.

Without the layer of water, the temperature of the furit surface may well fall below 0'C, as the air temperature in winter in cold countries is generally much below 0'C. The fruit, which is in direct contact with the cold air, will eventually attain a temperature below the freezing point of water.

air,...............