1. Flight It’s all about air Lift pulls upward
Drag and resistance slow things down Thrust and force speed things up
Gravity pulls down

2. Air is everywhere…. Or is it?
Some questions about air:
What is air?
Where is there no air?
If you play the cymbals in space, can anybody hear it?
How can air slow things down?
How can air lift things up?
Why doesn’t all the air escape Into space?
Air is a collection of molecules—very small particles that we cannot see—that cover the surface of the Earth. Air is comprised of 78% nitrogen, 21% oxygen, and the remaining 1% is mostly argon and carbon dioxide.
You can remove the air in a vacuum. Space is a vacuum
Sound needs to vibrate air particles
Air brakes, pneumatics
Aerodymanic design for lift, hot air balloon
Gravity pulls on air just like it pulls on a person and all objects. The weight of air is called air pressure and it pushes on us all the time. The existence of air pressure is what enables airplanes to fly.

3. Air pressure
In designing airplanes, trains, cars, rockets and bicycles—nearly everything that moves through the air—engineers must understand air.
The forces caused by moving air enable airplanes to fly and trains to slow.
Engineers take advantage of the nature of air pressure so their designs function correctly, efficiently and safely.
Engineers manipulate air pressure to create lift; they design wings so that the air moves faster over the top than under them, causing aircraft to lift during takeoff and during flight.

4. Experiment with air Can anybody do the cup trick?
Why does it work?

5. Figure 1. Air pressure acting on a person.
What Is Air Pressure?
Our atmosphere = a sea of air about 80 kilometers thick surrounding the planet.
All of that air is pulled down by gravity.
The air pushes against us in all directions.
This is air pressure.
Figure 1. Air pressure acting on a person.
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Why don't you feel the air pressure? (Answer: Your body pushes out against the air to balance the air pressure.)
Why don’t you feel air pressure?

6. How Does Air Pressure Work?
Air is pushing on all people and objects with a force of pounds per square inch at sea level.
As you go higher in elevation, less air is pushing down, so the air pressure is less. The change is not that great until you get very high.
Heating the air, cooling it, or causing it to move can change the air's pressure. These differences in air pressure create wind, and make flight possible.

7. Fold a paper in half lengthwise
When you blow through the tent, will the air velocity be greater on the inside or outside of the tent?
The tent walls will move (in / out / up) when you blow through the tent.
Bernoulli’s Principle states that as air moves faster over a surface, the pressure exerted on the surface (increases / decreases).

8. Apply Bernoulli’s principle
Start with balloons 4-6” apart.

9. What Is Bernoulli's Principle?
Bernoulli discovered that the faster water moves over a surface, the lower the pressure the water exerts on that surface. In Figure 2, water flowing out of a bottle moves faster through the narrow neck than it does in the rest of the bottle. Bernoulli proved that the water pressure on the sides of the neck of the bottle were less than those on the sides of the rest of the bottle.
Bernoulli then found that these same principles apply to air as well. Bernoulli's principle simply states that the faster a fluid moves over a surface, the less it pushes on the surface.
When designing airplane wings, engineers shape them so that they create lift. Even cars and trains are designed to take advantage of this principle, helping moving vehicles to stay on the ground at high speeds.
Figure 2. Fluid moving out of a bottle.
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Figure 3. The influence of air movement on air pressure.
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10. What would make a car fly?
5 flying cars.

11. What does it take to make something fly?
Design a high flying plane and find the best angle for an efficient wing.

12. Air pressure is caused by the rotation of the Earth.
True or False:
Air pressure is caused by the rotation of the Earth.
The faster air moves, the higher the pressure.
Air pressure pushes in all directions.
True or False: Air pressure is caused by the rotation of the Earth. (Answer: False. Air pressure is caused by gravity pulling air towards the Earth.)
True or False: The faster air moves, the higher the pressure. (Answer: False. Pressure decreases as air velocity increases.)
True of False: Air pressure pushes in all directions. (Answer: True. Air pressure not only pushes down on us, but it also pushes from the sides and even from below.)