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Anonymous asked in 科學及數學其他 - 科學 · 1 decade ago

熱學Radiation

黑色既物質會放熱放得好過白色如果溫度比外界高。

人體正常體溫38度,但香港街頭點都唔會過38度啦=.=

咁唔係着黑色衫會比較易散熱過白色咩:o

5 Answers

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  • 天同
    Lv 7
    1 decade ago
    Favorite Answer

    Wearing black cloths could lose heat betterthan white clothes is true if and only if you are staying in an environment at temperature lower than your body temperature, e.g. in an indoor environment.

    However, if you are staying under the sun, the reverse is true. Because the sun is at a higher temperature than your body (i.e. more specifically, the infrared spectrum of the sun, which composes of mainly near infrared, is of energy much higher than that of the infrared spectrum of your body, which is mostly far infrared). White clothes could reflect the heat (near infared) from the sun far batter than black clothes. Therefore, you would feel more comfortable in wearing whilt clothes under strong sunshine.

    Having said that, be aware that to have comfortable feeling in a hot summer day actually depends on a number of factors, the absorption of heat by clothes is only one but not all of these factors.

    An important factor is the relative humidity of the air, which governs the evaporation of sweat produced by your body. One would feel more comfortable in a dry air environment than in a wet one. Other factors include the wind speed in the surrounding air, and the temperature of the environment (radiant temperature).

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  • 1 decade ago

    黑色吸熱快.散熱都快

    如果著黑3,佢吸既熱快過散熱,所以熱個陣唔好著黑3,而白色唔會吸熱

    Source(s): ME
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  • 不需要學過物理

    學過中二地理的人都知道

    在一年內,地面係一個吸熱快散熱快的東西,和海洋相反

    夏天為地面吸熱的時間,地面會比海洋熱

    冬天為地面散熱的時間,地面會比海洋冷

    因此,季候風才會形成(夏天海風吹向大陸,冬天大陸風吹向海)

    將這個原理套入黑色衫

    黑色衫在猛太陽時會吸熱,熱會儲存,溫度會升到很高(在真空中不停上升)

    相反黑色衫在沒有太陽就可以散熱

    因為有太陽吸熱比散熱快

    雖然着黑色衫會比較易散熱過白色這說話是對的

    但在猛太陽時黑色衫吸熱吸得更厲害,溫度會上升

    白色衫吸熱較慢,溫度也會上升但比較慢

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  • 1 decade ago

    我未正式學過Heat,

    我諗會吾會係大陽經輻射入我地身體時,

    大部份熱量流失了

    但人體正常體溫是把熱量保存,故有38度!

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  • 1 decade ago

    呢個系因為黑色物體吸熱快.散熱快..而白色物體剛剛相反。

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