2006-06-28 08:34:12 · 7 answers · asked by 29luver 1 in Science & Mathematics ➔ Chemistry
note: when we force a breath from our open mouths across our skin, it feels warm, unless we force it out through a smaller pucker-mouth opening...
2006-06-28 09:50:58 · update #1
It isn't evaporation per se. Rather it is the disruption of the boundary layer. The skin is surrounded by a layer if still air that is warmed to body temperature. Moving air disrupts that still layer and cools us.
2006-07-11 11:05:48 · answer #1 · answered by Anonymous · 0⤊ 1⤋
The enthalpy ( usable energy) of a moving thermodynamical system is higher than the one of the static system. That 's why the wind cools the surface - it absorbs the heat from the surface.
THe mouth blow: when blowing with open mouth, the speed of the air is slow, so the heat can be transfered from the air to the skin. When blowing thru a small hole, the speed is high, so no heat is transfered from the air to the skin, but vice versa, because of the phenomenon described above.
2006-07-12 08:14:34 · answer #2 · answered by Vlada M 3 · 0⤊ 0⤋
When wind blows, the hot air rises up since it is lighter than the cold air. When hot air rises, the cold air decends which is felt by the body when wind blows. The wind usually blows due to pressure difference in two different regions.
2006-06-28 17:08:21 · answer #3 · answered by Munir B 3 · 0⤊ 0⤋
Tugboat's got it. The breeze blowing by your skin evaporates moisture (sweat) which cools the body.
2006-06-28 15:51:29 · answer #4 · answered by Dave_Stark 7 · 0⤊ 0⤋
Evaporation of perspiration
2006-07-11 23:56:22 · answer #5 · answered by Aldebaran 2 · 0⤊ 0⤋
evaporation of moisture on the skin
2006-06-28 15:42:27 · answer #6 · answered by Anonymous · 0⤊ 0⤋
Hey...I feel cool when my molecules are moving fast.
I feel even cooler when I am driving my Lamborgini.
2006-07-11 23:49:08 · answer #7 · answered by Thomas C 4 · 0⤊ 0⤋