I got this question on my physics test "What will happen if you blow over a piece of paper?" I answered that with enough blowing, the wind created would make the paper fly off. Apparently according to my teacher, the correct answer was that from Bernouilli's theorem, the air velocity above the paper will increase, the pressure will decrease and the paper will rise up. But how is that possible? Bernoulli's theorem applies only to a moving fluid whose speed is increased by decreasing the cross sectional area. In blowing, we are creating a high pressure inside the mouth and then releasing the air. The static pressure of the air remains the same all the time. Besides, a paper is held down due to gravity and air pressure. To lift a paper by creating low pressure on top of it would require quite a lot of low pressure plus quite a bit of normal pressure air below the paper.