Why use straws to suck water Beverages ?
When you use a straw to drink soft drinks, you have a fleeting question:
why does the mouth just suck once the water immediately follows a straw running into our mouth right away? It is mainly due to the help of atmospheric pressure.
We know that around the Earth there is a fairly thick layer of air, called the atmosphere. Where there is air, it is subject to atmospheric pressure. At the surface of the Earth, the atmospheric pressure on the area per square centimeter is about 10 newtons.
Plug the straw into the water cup, the inside and outside of the straw are all exposed to the air, all affected by atmospheric pressure, and the inside and outside atmospheric pressure are equal. Then the water inside and outside the tube is maintained on the same horizontal plane. We suck the straw and suck one, the air in the pipe is sucked away, in the airless tube, the pressure acting on the water inside the straw is smaller than the pressure acting on the water outside the pipe. smoking. So the atmospheric pressure immediately forced the drink into the straw, causing the water surface in the straw to rise. If we continue to smoke like that, the drink will be constantly pouring into our mouths.
Keywords: Straws; Atmospheric pressure.