Air Pressure and its properties

A lot of activities we do is because of the air pressure

When we sip through straw the liquid rises up because of air pressure

We are able to fly kites because of air pressure

Flags flutters because of air pressure

Let's perform an activity to understand how air exerts pressure

Take a bottle with a cap and fill it upto half with water

Now heat this for a little while and then remove it from the burner

Now pour cold water over it

We see that the vessel gets distorted

This is because the air outside exerts more pressure than air inside

Thus we see air exerts pressure

High speed winds are accompanied by reduced air pressure

Let us see how pressure is reduced when high speed wind passes with an activity

Take two balloons and inflate them and keep them at a distance of 10 cm

Now blow air between the balloons

We observe that the balloons come closer

This is because the air pressure between the two balloons reduces when wind is blown between them

Thus the air pressure in the balloons pushes them towards each other

Thus high speed wind creates an area of low pressure and as a result the surrounding area becomes high pressure

Winds also move from a region of higher pressure to lower pressure

The warm air rises above causing a low pressure zone while the cold air from surrounding high pressure zone rushes to fill the low pressure zone

As a result there is a movement of air leading to formation of winds

Revision

Air exerts pressure everywhere and this is known as atmospheric pressure

The air pressure created can be of two types low pressure and high pressure

The warm moist air creates a region of low pressure while cold air creates high pressure region

When the warm air rises up, the cold air from high pressure rushes into the low pressure zone resulting in formation of winds

The End