As we know air is everywhere and we can 't survive without air. It consists of various gases, dust particles, water vapors, etc. Air exerts a particular pressure on every single thing. Air pressure is calculated with the help of an instrument called barometer and according to it, the Earth 's atmospheric pressure is 14.7 psi (pounds per square inch). We can 't feel this pressure because it is everywhere. But if we are in a vacuum or in outer space where there is no air we have to use pressurized suits to protect our body. This is the reason why astronauts wear space suits. Here we are going to take a look at some air pressure experiments which will prove the existence of air pressure and will show that it has weight too.
Interesting Experiments to Measure Air Pressure
The experiments given below are easy to perform and need few things which are easily available at home.
Take a glass jar and empty it completely. Add small pieces of marshmallows inside the jar and seal it with a wine vacuum cork. Attach a manual pump over the cork and try to pump as much air out of the jar as you can. This will make the marshmallows pieces swell and you will observe them growing. Now break the seal. As soon as the seal breaks and air comes rushing inside the jar, the marshmallows cramp down and return to its old size.
Water Glass Experiment
This is one of the best experiments to measure air pressure. Take a glass and fill one-third of it with water. Place a cardboard over the mouth of the glass. The cardboard should be bit bigger than the glass ' mouth. Now apply some pressure on the cardboard from the left hand and invert the glass with the right hand. Slowly remove the hand and see what happens. The water does not fall from the glass, retaining the cardboard and the water in the same place as before. This takes place because the air pressure outside, i.e., 14.7 psi, is heavier than the combined weight of water and air inside the glass.