Atmospheric Pressure

Atmospheric Pressure

What is it?

What can air do???

Air can affect the shape of things. How? A bike tire feels squishy when it goes flat because it does not have enough air in it. You have to pump it full of air to make it firm again. So, how does adding air to a bike tire help it keep its shape?

How does adding air to the tire inflate it?

The tire is inflated when you add air because the pressure inside the tire increases as more air is added.

Multiple Choice

What is atmospheric pressure?

• weight of wind

• weight of air pushing down on an area

• weight of the time air takes to move

What is atmospheric pressure?

• Atmospheric pressure is the weight of the air pushing down on an area

• Atmospheric pressure is often measured in millibars

The term “air pressure” is used in reference to the weight of air molecules pressing down on the earth. At sea level, air pressure is generally 14.7 psi (pounds per square inch), which means that 14.7 pounds are pressing down on every square inch of our bodies. The reason we can still move our bodies freely is because the air is exerting pressure on us in all directions, and the reason we aren’t crushed is because the air pressure inside our bodies is the same

Multiple Choice

How is atmospheric pressure related to air density?

• higher density equals lower pressure and lower density equals higher pressure

• as density gets higher or lower atmospheric pressure does nothing

• higher density equals higher pressure and lower density equals lower pressure

How is atmospheric pressure related to air density?

• Pressure increases as the density of air increases

• Pressure decreases as density decreases

•  Density is a property of matter that is equal to the amount of mass in a certain volume of matter

What is density?

How closely molecules are packed

Multiple Choice

How are atmospheric pressure and density related to altitude?

• Atmospheric density and pressure decrease with increasing altitude.

• The two are not related

• Atmospheric density and pressure increases with increasing altitude.

How are atmospheric pressure and density related to altitude?

• The density of air in the atmosphere decreases as altitude increases because gravity pulls air downward

• The air at the bottom of the troposphere is compressed by all the air above it. Therefore, air is more dense at sea level.

• Sea level is the elevation of the land surface where the atmosphere meets the ocean

Multiple Choice

What causes the relationship between atmospheric pressure and density?

• Earth's orbit

• Earth's rotation

• Earth's gravitational pull

Thus, there is a cause-and-effect relationship between altitude and atmospheric pressure. A cause-and-effect relationship is a connection between events in which one event is caused by another event. When altitude increases, atmospheric pressure decreases; this relationship can help you predict how atmospheric pressure will vary from place to place in the world.