When we open mouth narrowly and releases air, cold air comes from it.when we open it widely and do so,hot air?

Question

When we open mouth narrowly and releases air, cold air comes from it.when we open it widely and do so,hot air?

Answer 1

It has to do with the Laws Of Physics. Air that is moving fast or at a low pressure has a lower relative temperature than air that is not moving or at a higher pressure.

This is why air at high altitudes is very cold, even on a warm summer day. You will also notice this chilling effect when you spray air from a high-pressure hose, a spray-can for cleaning off machinery, keyboards, etc., or even from a fire extinguisher, as the nozzle gets very cold and can even form a layer of frost on the surface. In extreme conditions this icy layer can block the hole the air is coming from and you will have to wait until it thaws before you can continue.

When you force air from your lungs while constricting your lips to a small "o" shape, you are accomplishing both pressure change and speed change because the air is exiting your mouth at a high rate of speed, and the air pressure inside your mouth is higher than the air pressure outside your mouth. This makes the air exiting your mouth seem colder than usual. If you open your mouth wide and simply exhale gently, there is very little pressure change or speed added to the air movement, so the air you are exhaling reflects the warmth within your body.

Answer 2

hey friend, the hot air coming from our mouth does not have any relation with the widening of our mouth, during respiration when the fresh atmospheric air comes in our lungs, the oxygen content of it is absorbed by our blood and the rest of the air which is oxygen less is exhaled out, due to our body temperature  this air is hot and when we exhale it either through narrowly opened or widely opened mouth in both cases it is hot.

           and in other case we only blow the air  with pressure which is in our mouth. and this air is cold because it has not experienced our body temperature. ok thank you

Answer 3

its bcoz of d air pressure

as pressure increases d temp decreases(narrow mouth)

vice versa for open mouth

Answer 4

It's not the fact that your mouth is wide or narrow that effects the temperature, it's how hard you're breathing. You can blow hot with lips narrowed, as long as you're breathing slowly. It's hard (or impossible) to blow quickly with a widely-opened mouth, though. Try it.

Answer 5

lol what IS this question doing in zoology lol

But anyways, its not how your lips are positioned, its how deep youre breathing from. Open your mouth wide && blow. The air is hot as youve said, but make your lips narrow && try to blow air from down deep in your lungs && not just from you mouth. The air will be hot as well if you do it correctly.

Answer 6

just use BERNAOULLIS THEOREM