State two experiences that made you think that air exerts pressure (other than those given in the text)

(a)Take a piece of thin sheet of polythene from any used packaging bag. Hold it close to your mouth and suck-in the air. What do you observe? The sheet sticks to the lips and gets pulled inwards. Why is it so? That is because the air outside exerts pressure inwardly.
(b) Take a balloon and blow it up. Press it gently. You have to apply some force to press it. What is exerting pressure from inside? This is the air inside that exerts pressure.