how are we able to change the temp of our breath by changing the shape of out mouth

[Guest gabo]

If you put your hand in front of your face and blow with your lips tight it will feel cool... then if you have your hand the same distance away and open your mouth wide and blow it's hot. Does anyone know why... I know it's real stupid but I was thinking about this and cant figure it out

[clubkat]

bwahahaha

::but it makes sense::

[njitpimp]

When you make your mouth smaller it speeds up the air, thus the colder temperature. Your wide open mouth lets the air come out slower, keeping it at a more normal body like temperature.

[joeg]

Originally posted by njitpimp

When you make your mouth smaller it speeds up the air, thus the colder temperature. Your wide open mouth lets the air come out slower, keeping it at a more normal body like temperature.

Thats it exactly.

[Guest gabo]

Originally posted by clubkat

bwahahaha

::but it makes sense::

what, why are you laughing at me?? it was an honest question. These are the things they didnt teach me in school.

[thehacker]

Originally posted by njitpimp

When you make your mouth smaller it speeds up the air, thus the colder temperature. Your wide open mouth lets the air come out slower, keeping it at a more normal body like temperature.

damnit!

and i was all ready to come onto this thread

and drop my science on it.

[joeg]

Originally posted by thehacker

damnit!

and i was all ready to come onto this thread

and drop my science on it.

Just make something up.... They'll believe it coming from you, lol.....

[loch]

Originally posted by njitpimp

When you make your mouth smaller it speeds up the air, thus the colder temperature. Your wide open mouth lets the air come out slower, keeping it at a more normal body like temperature.

i'll drop the science for you, hacker.

njitpimp is right, but what he conveniently left out is an explanation on the difference in "speed".

in either instance, the force of you breathing out is the same. however, when you constrict the opening of your mouth, and because the force of breathing/blowing is the same but the exit path is smaller, it creates a higher pressure jet stream. this higher pressure flow of air also creates a "draft" as it hits your hand. the draft then disperses/dissipates the hot air once it hits your hand.

when you dilate the opening of your mouth, again, the force of breathing/blowing out is the same, but because you have a larger opening, the pressure of air flowing out is lower. thus, the hot air lingers longer without the benefit of the draft that was created in the high-pressured air.

in either instance, the temperature of the air you blew out did not change. it is the effects you feel, the sensation rather, of having a draft that disperses the air that makes it feel cooler. think of a 95 degree windy day versus a 95 degree no wind day. which feels cooler?

did i bore you to death?

[thehacker]

molecules tend to move more rapidly

from a space of high pressure to a space

of lower pressure...

BROWNIAN MOTION

by constraining your mouth and blowing

you are creating a higher pressure space

in your mouth than usual, and thus,

the molecules tend to more more rapidly

from a space of high pressure (your mouth)

to a place of lower pressure

(the outer atmosphere / your room)

[sttarrkidd]

can i have a piece of the science too...

it also has to do where the air is coming from... when you open your mouth, your soft pallette relaxes and causes you to have to breathe from your diaphragm, so the air is warm, whereas, the cool air is already sitting somewhere where it has chilled for a while cuz the air is not coming directly from the diaphragm.... see i do learn something even tho i am theater major...

pixie dust

starr

[clubkat]

u guys are nuts ::and super smart!::