AIR PRESSURE
What properties
does AIR have?
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Mass
Density
Pressure
Volume
Mass/Volume
What is density?
* think of a balloon
filled with AIR
*AIR is less dense
than water
because the
molecules in AIR
are spread further
apart.
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The amount of matter in a given space
How “crowded” the molecules
What is pressure?

The force pushing on an area
* think of water
pressure- the
deeper you go the
more pressure is on
your body
What is AIR
pressure?

A force that is the result of the weight of
a column of air pushing down on an
area
*even though you
cannot see the air,
it is pushing down
on you (gravity)
How do you
measure AIR
pressure?

A tool called a barometer
o Aneroid barometer
o Mercury barometer
What is an
aneroid
barometer?
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
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“Without liquid”
Metal chamber with springs
Measures AIR pressure
*illustration
*illustration
What is a mercury
barometer?
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Glass tube
Opened at the bottom
Filled with mercury
Measures AIR pressure
What are the 2
units used to
measure air
pressure?
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Inches
Inches of mercury
What is altitude?

Distance above sea level
How does altitude
affect air
pressure? Why?

Air pressure is higher at sea level because
it is the lowest point. There is more air
above it pushing down.
How does altitude
affect the density
of air?

As altitude increases (the higher you go),
the less dense the air is because there
are less molecules in the air.
Air at sea level is most dense
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