Atmosphere and Air Pressure Notes

Define atmosphere • Atmosphere – The whole layer of air that surrounds Earth – A mixture of gasses – Keeps Earth warm – Protects life

Why is the atmosphere important?

• • • • • Protects life Keeps the Earth Warm Allows talking/sound Provides weather Allows flight

How does the atmosphere protect life?

• • • Absorbing harmful radiation Maintaining Earth ’ s temperature Providing elements essential for life

What materials make up the atmosphere?

Gas Nitrogen (N 2 ) Oxygen (O 2 ) Argon (Ar) Carbon Dioxide (CO 2 ) Other Elements Water Vapor (H 2 O) Percent 78.08

20.94

0.98

0.04

0.01

0-1

Gases of Earth's Atmosphere

What can change the atmosphere?

• Natural Changes – The exact amounts of some gases in the air (atmosphere) change depending on: • Location • Time of day • Season

What else can change the atmosphere?

• Sudden Changes – Dramatic events may cause a change in the atmosphere – It may take a long time for the atmosphere to restore balance – Examples • Volcanic Eruptions • Forest Fires • Dust Storms

Define Altitude •

Altitude

The distance above sea level

Define density • Density – – The amount of mass in a given volume The density of the atmosphere decreases with altitude Most of the mass of the atmosphere is close to Earth ’ s surface

What is air pressure?

• • • Air Pressure – The force of air molecules pushing on an area.

Air pushes in ALL directions Greater the force the higher the air pressure

How does air pressure relate to density?

• Air pressure and density are related – As density increases, air pressure increases – As density decreases, air pressure decreases

LOW AIR PRESSURE HIGH AIR PRESSURE

How does air pressure relate to altitude?

• Air pressure decreases as you move higher in the atmosphere.

– High Altitude = Low Air Pressure – Low Altitude = High Air Pressure

Why dont you feel air pressure acting on you?

• It is balanced. – The pressure pushing down on you is balanced by the pressure of air pushing up from below.

How do we measuring air pressure?

• Barometer – Any instrument that measures air pressure

How did air pressure keep the card on the cup?

How did air pressure get the balloon in the glass bottle?

How did air pressure crush the can?

How did air pressure keep the ping pong ball in the funnel?

How did air pressure keep the ping pong ball floating?