Answer
When we suck the air out of the straw, the pressure inside the straw decreases. This allows the higher pressure on the other side to push the fluid up the straw and into our mouth. Because it is really the atmosphere that is doing the pushing, the atmospheric pressure limits how high will it go up in the straw. At sea level, the air pressure is enough to support a column of water about thirty feet high.
Work Step by Step
When we suck the air out of the straw, the pressure inside the straw decreases. This allows the higher pressure on the other side to push the fluid up the straw and into our mouth. Because it is really the atmosphere that is doing the pushing, the atmospheric pressure limits how high will it go up in the straw. At sea level, the air pressure is enough to support a column of water about thirty feet high.
