本题目来源于试卷: gc textbook chater 14 heat,类别为 通用国际物理
[问答题]
Down sleeping bags and parkas are often specified pr +gvnm o2o27as so many inches or ce2,tqeiud68u3oa/ edn fjs:s ( ntimeters of loft, the actual thickness of the garment when it j3(t 28 fded/ano ,6:iusesquis 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.
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