2006-07-19 08:02:17 · 9 answers · asked by larry j 3 in Science & Mathematics ➔ Physics
First you must correctly define "cold". It is the absence of heat. Heat is defined at particle energy of a system.
If you are out on a still, calm day, your body's heat energy will radiate off of you and the energy will raise the temperature of the system of air immediately around you. This is why if you stand in the sun on a winter day thathas no wind, even without a shirt on you would feel comfortable.
Now, if the wind is blowing, that heated system is taken away from you. Even if the ambient temperature is above say 100 degrees F [i.e. above your body temp], it will still feel "cooler" because the heat energy of your body is being drawn away better than in still air. This is why all nautical survival instructions talk about not treading water unless you have to if your boat sinks. If you have a flotation jacket on, keep your arms at your sides and legs together and as still as you can. By moving them around it creates a "wind" in the water which draws out the body's heat more quickly. By not swirling the water around the body, the water system immediately around will have its temperature raised a bit. So, it's all about the transfer of heat energy. Now, if you ask, well then why doesn't the moving air coming out the back of jet engine make on feel cooler, it's cause THAT air has lots and lots and lots of heat energy and energy wants to go from high energy system to low energy system. That low energy system would also include the body of the person standing in the jet blast.
2006-07-19 08:15:03 · answer #1 · answered by quntmphys238 6 · 5⤊ 0⤋
For two reasons. First, when you contact moving air, you're encountering more air mass that your body is trying to warm up. This can be seen when cool objects touch the skin. The more dense (and conductive) materials, like metal, will always feel colder than something less dense (like wood) even though the two materials are at the same temperature.
Second, there is something called evaporative cooling that happens when liquids evaporate off of a surface. They cool the surface slightly. Evaporation is sped up by wind movement.
2006-07-19 08:17:12 · answer #2 · answered by Favoured 5 · 0⤊ 0⤋
Well, it not only feels colder... it is colder than the air around you. This is practiced when you blow on your spoon full of hot soup to cool it off. when you're still, you heat the air around you, and the air becomes warmer (so technically, you're in warmer air than the atmosphere). If wind comes along, it blows the hot air you have around you away, and blows in new air, which is cold.
2006-07-19 08:12:00 · answer #3 · answered by M 4 · 0⤊ 0⤋
Coolness is linked to airs ability to hold moisture. The drier air is the more moisture it evaporates from your skin making your sweat (and natural oils) cool you.
Likewise the MORE air that comes into contact with your skin the faster this cooling will take effect, regardless of how hot or cool the atmosphere around you is.
2006-07-19 08:06:59 · answer #4 · answered by cirestan 6 · 0⤊ 0⤋
'cause it tends to evaporatively cool you by taking the warm water (sweat) on your body, and giving it a little kick, enough to have it vaporize off your body (enough energy to reach escape velocity, having been pushed over the edge), taking a little energy away from your body, thus cooling it. Conservation of energy says you can't create or destroy energy, just change its form. Water vaporizing basically takes heat energy and converts it into kinetic energy, removing energy from the overall system that is your body.
Non-moving air doesn't tend to as readily kick off or absorb the water vapor, so you won't get that evaporative effect as readily. It'll happen, just much slower.
2006-07-19 11:45:24 · answer #5 · answered by Michael Gmirkin 3 · 0⤊ 0⤋
It all comes down to the wind chill effect. The faster you move, the faster heat is taken aways from the surface of the skin, making you feel cooler!
Simple as that, hope it answered your question!
2006-07-19 08:23:19 · answer #6 · answered by Anonymous · 0⤊ 0⤋
Air has the ability condense water from your body (sweat) As the sweat produce heat is los throuh the sweat
2006-07-19 12:14:44 · answer #7 · answered by miami 1 · 0⤊ 0⤋
Warm air can feel cooler because it is drying the moisture on your body,which is the body's way of cooling off. I think it is called wicking.
2006-07-19 08:07:45 · answer #8 · answered by Anonymous · 0⤊ 0⤋
due to convection heat is carried from the body and taken away by passing air.
refer convection heat equation
the more the velocity and temperature difference the heat convection willbe more.
2006-07-19 08:08:08 · answer #9 · answered by dhamas 3 · 0⤊ 0⤋