Air Exerting PressureAir exerts pressure.It can be seen in the following activity.
Take a tin can with a lid. Fill it approximately half with water. Heat the can on a candle flame till the water boils.Let the water boil for a few minutes. Blow out the candle. Immediately put the lid tightly on the can.Now if you will pour cold water on the can you will observe that the can get compressed.
Conclusion: This happens because when the water is poured over the can, some steam in the can condenses into water,reducing the amount of air inside. The pressure of air inside the can decreases than the pressure exerted by the air from outside the can. This proves that air exerts pressure.
Quick Summary With Stories