Pressure Exerted by Air

Deep sea divers experience more pressure than regular swimmers.

This is mostly because water pressure increases with the depth of the sea.

When a swimmer is at the surface of the sea, water exerts very little pressure on him.

Deep-Sea divers on the other hand dive deep into the water and experience more pressure.

As the diver dives deeper and deeper, the pressure exerted by the water keeps increasing.

Likewise, the air around us also exerts pressure on us.

However, this pressure exerted by the air cannot be felt by us.

This is because our body exerts an equal pressure in the opposite direction to counter the air-pressure.

The two equal pressures working in the opposite directions balance each other and hence we are unable to feel the air-pressure.

A lot of our daily activities like the inflation of tyres, drinking out of a straw etc. depend on this simple concept of Air-Pressure.

Let us see how air pressure enables us to drink out of a straw.

When we suck through a straw, the liquid moves up the straw and reaches our mouth.

This is because when we suck on a straw, we essentially suck the air out of it.

This results in a drop of pressure within the straw.

The atmospheric pressure becomes higher than the pressure inside the straw.

This difference in pressure causes the atmospheric pressure to act upon the liquid and pushes the liquid into the straw.

Due to the pressure exerted by the atmosphere on the liquid, it starts flowing within the straw and reaches our mouth.

The interaction of air molecules with the liquid allows the liquid to flow within the straw.

Therefore, we can say that the exertion of air pressure is a result of the way air molecules interact with the objects.

Let us briefly discuss the interaction of air molecules with objects around us.

Let us consider a simple table as shown above.

Now we know that we are surrounded by air molecules everywhere and these molecules are at random motion.

The air molecules around the table, in reality, are constantly interacting and colliding with the table.

Due to the collision, the air molecules exert a force on the object or in this case, the table.

The table, in return, exerts an equal and opposite force on the air molecules due to which the table does not crush under air pressure.

Similarly, Earth is surrounded by a layer of atmosphere and the atmosphere contains millions and millions of air molecules.

The air molecules in the atmosphere exert force on the Earth.

This force exerted by the air molecules in true sense is the Air-Pressure.

Revision

The pressure created by air molecules on every object is known as Air Pressure.

Every object exerts equal and opposite pressure on the air molecules due to which they do not get crushed under air pressure.

The End