A straw extends out of a glass of water by a height h. How fast must air blow across the top of the straw to draw water to the top of the straw?

Question

Answer 1

The speed of the air blowing across the top of the straw depends on the density of the air, the density of the water, the height of the straw, and the diameter of the straw. Generally, the speed of the air must be greater than the speed of the water rising up the straw due to the pressure difference between the top and bottom of the straw.