State two experiences that made you think that air exerts pressure.
We have experienced that when we blow a balloon, the balloon becomes tight. If we try to fill more air, then the balloon will burst after an extent. This happens because air exerts pressure.
We have also experienced the movement of fringes of windows and doors of our houses when wind blows in a high speed. This also happens because air exerts pressure.
1) Balloons and balls can be used only when they are inflated with air. When balloon is overfilled with air it bursts due to excessive air pressure.
2) Compressed air is used in the brake system for stopping trains.