Friction

[matty2670]

If friction causes heat, why does the air feel cold if you stick your hand out of a car window?

[CT]

Your body has greater heat than the friction from the air. Therefore you lose body heat.

[matty2670]

Thank you. Believe it or not, I'm actually reasonably intelligent...

[mibn2cweus]

Hi matty2670! Believe it or not I too am satisfied with my level of intelligence for the most part. I actually believe that CT�s answer is quite good and superior to what I first had in mind but if you don�t mind a little extra input I was considering evaporation of perspiration as a contributor to the elusiveness of the heating effect of friction due to air blowing against your hand. Another feature which comes to mind as I am writing this is that much of the heat gained from friction would be quickly carried away by the heat exchanging properties of the air itself. These are not too carefully considered answers but perhaps they give you some other things to think about thereby helping you to keep up that mental prowess of yours. Believe it or not I believe it helps me so thank you for the question.

[PhilBy]

Could it be that air has a low friction level. :-) A hand stuck of a car window will feel the outside temperature, minus the wind chill factor + the heat caused by the level of air friction. (Both the wind chill factor & the level of air friction being determined by the speed of the car)

Now if you were to put your hand out the space shuttle window when re-entering earths atmosphere ...............

[gary baldy]

I know this cos i had a big argument about it with my mate.
Moving air causes a vortex as it passes over you skin and the temperature within this vortex drops thus lowering the temperature of your skin.

[gerogiaxox]

because as your body heat is alot more than outdoor air, the air brushing your hand is taking away the heat energy with it, making your hand feel coolness