What Is Air Pressure? — Reading Comprehension

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This audio-integrated reading passage delves into the foundational concept of air pressure, aligning with the NGSS Disciplinary Core Idea of Physical Science (PS3.A: Definitions of Energy). The text explains how air pressure, the force exerted by the weight of air molecules, is a critical component of our physical world. It explores real-world applications of this principle, from how a straw works to the changes in pressure experienced at different altitudes. By defining key terms like "air molecules" and explaining the relationship between pressure and altitude, the passage provides a clear and accessible introduction to this scientific concept. It also touches on the connection between air pressure and weather systems, making the topic relevant and relatable. The passage incorporates keywords such as air pressure, atmospheric pressure, force of air, and molecules to enhance its SEO value and support students in grasping this fundamental physical concept. This resource is designed to support the understanding of how energy is stored in matter, specifically within the context of atmospheric dynamics.

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A glass filled with water, held upside down with a playing card underneath it, with arrows showing air pressure pushing up on the card. — Air pressure can be demonstrated by a simple cup of water and a card.

Have you ever wondered what keeps a balloon inflated or how a straw works? The answer is air pressure. Air pressure is the force exerted by the weight of air molecules on a surface. Even though we can't see it, the air around us is made of countless tiny particles that are constantly moving and pushing against everything. The higher you go in the atmosphere, the less air there is above you, which means the air pressure decreases. This is why your ears might pop on an airplane or when you drive up a mountain.

Air pressure is all around us, pushing on us from every direction. However, we don’t feel this immense weight because the pressure inside our bodies is the same as the pressure outside. A simple way to see air pressure in action is with a straw. When you suck on a straw, you remove some of the air from inside it, creating a lower pressure area. The higher pressure of the air outside the straw then pushes down on the liquid in your cup, forcing it up the straw and into your mouth. The same principle applies to using a syringe without a needle—you pull back the plunger, creating a low-pressure area, and the outside air pressure pushes liquid into the barrel.

Air pressure is also a key part of weather. High-pressure systems often bring clear, sunny weather, while low-pressure systems are typically associated with cloudy skies and precipitation. Understanding these systems helps meteorologists predict the weather.

Fun Fact: The air pressure on the surface of your body is about 14.7 pounds per square inch, which is over 2,000 pounds of pressure on an average-sized person!

What is the definition of air pressure?

The heat of air molecules on a surfaceThe color of air molecules on a surfaceThe weight of air molecules on a surfaceThe movement of air molecules on a surface

Where does air pressure decrease?

At sea levelIn a valleyOn top of a mountainIn a crowded room

Based on the passage, what would happen if you used a syringe and pushed the plunger in while it was in a liquid?

The liquid would stay in the cupThe liquid would be pushed back out of the syringeThe liquid would be pulled into the syringeThe liquid would overflow the cup

Why do our ears pop on a plane?

The air inside the plane is too hotThe pressure inside our ears is different from the outside pressureThe plane is moving too fastWe are going a long distance

What can you infer about weather systems and air pressure?

High pressure means rainLow pressure means clear skiesHigh pressure systems are associated with good weatherAir pressure has no effect on weather

If you filled a bottle with water and turned it upside down with a card over the top, what would prevent the water from falling out?

The bottle's weightThe card's thicknessThe force of gravityThe air pressure outside the bottle

Imagine you have a plastic bottle and you suck out some of the air with your mouth. What will most likely happen to the bottle?

It will stay the same shapeIt will expand and get biggerIt will shrink or crush inIt will float in the air

How could you demonstrate the concept of air pressure to a friend using an empty glass and a bowl of water?

By pushing the glass into the waterBy floating the glass in the waterBy inverting the glass over a candle in the bowl of waterBy filling the glass with water and letting it sit