1. What is happening when you press on your friend's arm?
Pressure
What is happening when you press on your friend's arm?

2. What is Air Pressure?
The force air molecules exert on something as they move around and are pulled down by gravity.

3. Weight of Air
Plungers and Vacuum Demonstration

4. What is Air Pressure A few demonstrations: Straw with water Balloons
Cup and Index Card

5. Changing Air Pressure

6. Temperature and Pressure
Bottle and Crushing Can Demonstration

7. Air Pressure: Changes What affects air pressure? Higher Temperature
air moving faster = more pressure
Amount of air
more molecules = more pressure
Volume
less room to move = more pressure

8. Air Pressure and Air Motion
Why does air leave an inflated balloon?

9. Air Pressure and Altitude
Because most air is held down to the Earth, higher elevations have lower air pressure.

10. Why do your ears pop with changing altitude?