本题目来源于试卷: gc textbook chater 14 heat，类别为 IB物理学
[问答题]
Down sleeping bags and parkacr96dx3)7ivb 8 lykmpr3 0zovs are ofte fz +mpm0x,dp-n specified as so many inches or centimeters of loft, the actual thickness of the garment whenfdm x,pp z0-m+ it is fluffed up. Explain.
参考答案:
When the garment is fluffed up, it will have the
most air trapped in its structure. The
air has a low thermal conductivity, and the more the garment can be “fluffed”,
the more air it will trap, making it a better insulator. The “loft” value is similar to the R value of
insulation, since the thicker the insulation, the higher the R value. The rate of thermal conduction is inversely
proportional to the thickness of the conductor, so a thick conductor (high loft
value) means a lower thermal conduction rate, and so a lower rate of losing
body heat.
本题详细解析:
暂无
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