1. Air Pressure

2. What is Air Pressure?
The weight of the air pushing down on us and everything else around us.
Happens because of the gravitational pull.

3. Air Pressure Why doesn't all that pressure squash me?
Air pushes on you with a force of 14.7 pounds per square inch. The force on 1,000 square centimeters (a little larger than a square foot) is about a ton!
Why doesn't all that pressure squash me?
Remember that you have air inside your body too, that air balances out the pressure outside so you stay nice and firm and not squishy.

4. ELEVATION Low pressure High pressure Higher elevation = lower pressure
Lower elevation = higher pressure
Low pressure
High pressure

5. HIGH & LOW PRESSURE SYSTEMS
Warm
Moist
Rising air
Counterclockwise rotation
HIGH PRESSURE
Cold
Dry
Sinking air
Clockwise rotation

6. Compare Warm Air and Cold Air
Warm, moist air = lower pressure (lighter)
Molecules spread out;
Fewer molecules in
a certain space
WARM AIR
Cold, dry air = higher pressure (heavier)
Molecules crowd together;
More molecules in
a certain space
COLD AIR

7. How does air pressure relate to weather?
Helps to determine if there will be rain or sunny skies; cold or hot air; etc…

8. Low Pressure systems Warm Humid Rainy Cloudy weather Thunderstorms
Severe weather
The warm air rises, condenses, forms clouds and rains!

9. Low Pressure Weather Results

10. High Pressure systems Sunny skies Cooler temperature Dry air
Beautiful weather

11. High Pressure Weather Results

12. Front Animations
Cold Front
Warm Front
Stationary Front
Occluded Front

13. Your Turn!!!
Now YOU are going to demonstrate air pressure by doing a Metal Can Experiment!!