Question

How is air pressure created?

Answer 1

Hint: Air pressure depends on mass of the air, gravitational force of the earth , composition of the gas and the way they are packed together. It plays a significant role in determining climate change.

Complete answer:
Air pressure is developed because of the weight of the air molecules . Every single molecule possesses some weight and collectively when all these molecules group together to form atmosphere they produce a significant amount of pressure. These molecules experience a gravitational pull from the earth.
Although most of the air is found in the range of $20Km$ from the earth’s surface, but the atmosphere spreads itself to about $50Km$above the earth’s surface.
For example, if we consider a $1{m^2}$column of air which is $50Km$above the earth’s surface, then it possesses a weight of about $10,000Kg$.
We know that the force of gravity of earth is defined as $mg$
$
\Rightarrow F = mg \\
\Rightarrow F = 10000 \times 9.8 \\
\Rightarrow F = 100000N \\
 $
We also know that the pressure is defined as Force exerted per unit area.
$
\Rightarrow P = \dfrac{F}{A} \\
\Rightarrow P = \dfrac{{100000N}}{{1{m^2}}} \\
\Rightarrow P = 100000N.{m^{ - 2}} \\
\Rightarrow P = 100000Pa \\
\Rightarrow P = 100kPa \\
 $
Hence, we prove that there is a significant amount of pressure created by the air.

Note: The pressure change in air causes weather changes. If high pressure is produced by the air, it starts flowing down which prevents the formation of clouds . Hence, the sky will remain clear. And if the pressure is low, the air starts flowing upwards. As it rises, it starts cooling down and forms water vapour. Then, they turn into tiny water droplets which form clouds. This leads to rain.