2007-02-10 15:56:19 · 8 answers · asked by casey g 1 in Science & Mathematics ➔ Physics
As another person said, this is caused by the difference in pressure above the paper vs. below the paper. This effect is described in Bernoulli's principle.
2007-02-10 16:02:26 · answer #1 · answered by jflinca 2 · 0⤊ 1⤋
I cannot replicate this. I can, however, blow straight at the edge of the paper and it will rise. The answer air is going beneath the paper but it would not rise if all things were equal. An airplane has lift because the design of the wing causes air pressure under the wing to be higher than air pressure it. The high pressure under the wing pushes it up towards the low pressure. The same with the paper when the airpressure under it exceeds that over it..
2007-02-10 16:08:57 · answer #2 · answered by cold_fearrrr 6 · 0⤊ 0⤋
Because it lowers the air pressure above the paper. Thus, air underneath pushes the paper up.
Here is a simplified way to think about it:
When you blow across the paper, then the air molecules above it are moving along it, instead of pushing on it. Imagine you and a friend are having a shoving contest, where you are shoving his hands and he is shoving yours. If you both push equally against each other, then no one goes anywhere. But if you try to shove to the side but your friend keeps pushing straight at you, he will push on through to you. You pushing to the side is like the air blowing ACROSS the paper instead of just pushing down on it as it normally does.
This is indeed "airfoil physics" and Bernoulli's law (those are both about the same thing), as the next two postings say.
2007-02-10 16:00:04 · answer #3 · answered by DadOnline 6 · 2⤊ 0⤋
bcz, when u blow over a paper the air pressure(which is equal before u blow) on the blowing side, moves in the direction of blowing hence resulting in formation of a low press. region over the paper , the air press. below the paper increases and start moving upward along with the paper
2007-02-10 21:39:41 · answer #4 · answered by Anonymous · 0⤊ 0⤋
The air your blowing out slips under the paper.
2007-02-10 15:59:27 · answer #5 · answered by Anonymous · 0⤊ 0⤋
because you are lowering the air pressure above the paper. It's simple airfoil physics such as that seen on an airplane wing.
2007-02-10 16:00:58 · answer #6 · answered by cav_scout_recon 2 · 0⤊ 0⤋
it lowers the air pressure above the paper
2007-02-10 16:05:54 · answer #7 · answered by futureastronaut1 3 · 0⤊ 0⤋
for a full answer, go here:
http://en.wikipedia.org/wiki/Bernoulli%27s_principle
2007-02-10 16:05:59 · answer #8 · answered by Walking Man 6 · 0⤊ 0⤋