What is Air Pressure?
There are countless small, microscopic air particles all around us all the time. Air can be squeezed to fit in a smaller amount because air molecules have a lot of "unoccupied" area between them. In addition to having mass, air exerts pressure also. While the term "air pressure" can be used to describe the force of air within a closed space, the term "atmospheric pressure" explicitly describes the force of air particles beyond a particular location in the Earth’s environment. In this article, let’s see more about how air exerts pressure with certain examples.
Air Pressure
Air molecules push throughout all directions and the pressure applied is known as air pressure. From the regions with extremely high pressure, air travels from there to areas where there is lower air pressure. The air moves more quickly when the pressure differential is bigger. Mercury can be used in the formula to measure air pressure.
Air pressure 𑁓 Density of mercury × acceleration due to gravity × height of the column of mercury.
Air pressure can be determined utilising atm, mm, Hg, Pa, and other units.
Example of Pressure
Certain example of pressure is listed below:
A labour senses the pressure of the weight carried upon his shoulders.
When a nail is pressed into a plank of wood, pressure is applied to it.
While cutting fruits using a knife, the knife exerts pressure upon the fruits.
Air Exerts Pressure Examples
The quantity of air within the can or bottle decreases when hot water is poured over it because a portion of the can's steam condenses into water. The pressure of the air within the can is lower than the pressure of the air outside. The outcome is that the can is compressed. This is one among the air exerts pressure examples and also the answer for why the shape of the can or a plastic bottle gets disoriented when we pour hot water in a plastic water bottle and close it tightly.
Atmospheric Pressure Examples
The two atmospheric pressure examples are listed below:
Sucker Hook - Air within the sucker hook is squeezed out when it is pressed, leaving a low air pressure environment. The hook sticks strongly to the wall due to the increased exterior atmospheric pressure outside.
Drinking Straw - The air in the straw is expelled when it is sucked, leaving a low air pressure region. Drinks were forced into the straw as a result of the higher atmospheric pressure acting upon the water’s surface.
What are the Effects of Air Pressure?
There are several effects of air pressure. Air has weight, and because of its mass, it exerts pressure. The motion of winds, which act as a means of moving moisture and heat through one area to another, is caused by variations in air pressure from region to region. Pressures are significant because of how they affect precipitation and temperature. The examples of the effects of air pressure are as follows:
Wind is caused by the effect of air pressure.
Storms arise as a result of the variation in air pressure.
They also contribute to the formation of the convective form of rainfall.
How is Wind Caused?
The primary cause of the winds is the unequal heating of the earth's crust. Increased heating causes the air to rise, which results in low pressure. As a result, the air at high pressure fills the area of low pressure that causes the wind. The winds change direction at dusk since air cools more quickly over land compared to over sea.
Difference between Air and Wind
The list of air and wind differences is explained in the tabular column.
Interesting Facts
A balloon is inflated by the air inside it, which applies pressure from all sides.
Moving objects experience resistance from the air. This is referred to as air resistance. Because of this, riding a bicycle requires a lot of effort and vigorous pedalling.
The term "anemometer" refers to the tool used to monitor wind speed.
Human body contains both air and liquids that create an internal pressure that counteracts the external atmospheric pressure. This keeps our bodies from collapsing from the pressure of the air surrounding us.
Key Features to Remember
We refer to the atmosphere as the air bubble that surrounds the world. Air has weight. Human bodies are constantly under pressure from air weight.
The air surrounding us exerts pressure. Wind is the movement of air.
Air grows as it is heated and shrinks when it is cooled.
Wind motions are mostly caused by uneven heating of the soil.
Rain is brought by winds bearing water vapour.
Cyclones can be caused when there occur any differences between high-speed winds and air pressure.
Conclusion
As a result, it can be concluded that humans have air and liquids inside their body that exert pressure on the external world, cancelling out the air pressure external to us. The gravity of the air surrounding won't cause human bodies to crumble as a result. Air constantly flows from a point of high pressure area to a place of low pressure area, which is one of the most crucial ideas to keep in mind throughout this article. It's common to feel the wind when air is moving from a high-pressure to a low-pressure area.
FAQs on Air Exerts Pressure
1. What does it mean when we say 'air exerts pressure'?
To say that 'air exerts pressure' means that the air around us, which is made up of countless tiny molecules with mass, is constantly pushing on every surface it touches. The collective force of these molecules striking a surface creates what we call air pressure. This happens in all directions—up, down, and sideways.
2. What are some simple examples from daily life that show air exerts pressure?
You can see air pressure in action in many common situations:
- Drinking with a straw: When you suck on a straw, you remove the air inside it, creating a low-pressure area. The higher atmospheric pressure outside then pushes the drink up the straw and into your mouth.
- Inflating a balloon: The air you blow into a balloon pushes against its inner walls from all sides, causing the balloon to expand. This demonstrates the pressure exerted by the air inside.
- Using a suction cup: When you press a suction cup against a smooth surface, you force the air out from underneath it. The greater air pressure on the outside of the cup holds it firmly in place.
3. If air exerts so much pressure on us, why don't we get crushed by it?
We are not crushed by the immense atmospheric pressure because the air and fluids inside our bodies exert an equal and opposite pressure pushing outwards. This internal pressure perfectly balances the external pressure from the atmosphere, creating equilibrium and preventing our bodies from collapsing.
4. How does air pressure cause wind to blow?
Wind is simply air moving from one place to another, and this movement is caused by differences in air pressure. Air naturally flows from an area of high pressure to an area of low pressure. This movement of air is what we feel as wind. The greater the difference in pressure, the faster the wind blows.
5. What is the difference between air pressure and atmospheric pressure?
While the terms are related, they have specific meanings. Air pressure is a general term for the force exerted by air in any given space, such as the air inside a car tyre. Atmospheric pressure specifically refers to the pressure caused by the weight of the entire column of air in the Earth's atmosphere pressing down on a particular point.
6. Why does a plastic bottle get distorted if you pour hot water in it and then close the lid tightly?
When hot water is in the bottle, some of it turns into steam, increasing the pressure inside. After sealing the bottle, the steam cools and condenses back into water. This reduces the amount of gas inside the bottle, creating an area of very low pressure. The significantly higher atmospheric pressure outside then pushes on the walls of the bottle, causing it to collapse or get distorted.
7. Why is the air pressure lower on top of a mountain compared to at sea level?
Atmospheric pressure is caused by the weight of the air column above a certain point. At sea level, there is a long column of air pressing down, resulting in high pressure. As you go up a mountain, the height of the air column above you decreases. With less air pushing down from above, the weight is lower, and therefore, the air pressure is lower.
8. How is the concept 'air expands on heating' connected to air pressure?
These two concepts are directly linked and explain how weather patterns form. When air is heated, its molecules gain energy and spread apart, causing the air to expand and become less dense. This less dense, warm air rises, leaving behind an area of low pressure near the ground. Cooler, denser air (which is at a higher pressure) then moves in to fill this space, creating wind.
