Why does sweating cool the body on a hot day?
ASweat absorbs sunlight to warm air around it
BSweat reflects sunlight away from the skin
CSweat reaches absolute zero temperature instantly
DEvaporation of sweat takes latent heat from skin
Answer & Solution
Correct answer: D. Evaporation of sweat takes latent heat from skin
1. Sweat is a liquid film on the skin.
2. Evaporation needs heat (latent heat of vaporisation).
3. This heat comes from the skin, cooling the body.
4. So evaporation of sweat cools the body.
_Source: Selina Concise Physics Class 8, Ch 5 Heat (Mistral OCR'd PDF), section on cooling by evaporation_
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