what is the importance of air pressure
Answers
Air pressure is simply the weight of all the air above us pressing down on us. Gravity is pulling the molecules of air down towards the surface of the earth and like a pileup in football, we’re on the bottom getting squeezed by all those molecules on top of us.
If there were no air pressure then there would be no air and life as we know it could not have evolved. Air pressure is what keeps the water in liquid form around the globe. The intermolecular forces of water are not sufficient. They need help (from air pressure) to hold together. With no air pressure, the water would have all evaporated away (ice caps too) and escaped off into space. Only subterranean water, where the pressure of the earth would hold the water would we find any water left. You can see this on Mars, which has a very low air pressure and where the surface is extremely dry but there are indications that there are underground supplies of water.
Without air pressure, we could not breath oxygen. We could expand our lungs but it’s the external air pressure that pushes the air into our expanded lungs. With no air pressure, we cannot ‘pull’ air into our lungs. Air has almost no tensile strength and cannot be “pulled”, no matter how strong the vacuum. Your vacuum cleaner works because air is pushed out of the chamber by the motor and then the external air pressure pushes in replacement air through the nozzle and hose, taking along with it the dirt you are trying to get rid of.