November is Aviation History Month. Bring aviation history to life this month with a focus on the science behind flight with hands-on activities that combine STEM, problem solving, and critical thinking. How can something as heavy as an airplane stay in the air? There are three laws of flight that allow planes to fly. Learn and experiment with them below.
Bernoulli’s Law of Pressure: The faster air flows, the less pressure it has.
When air is moving, it creates areas of high pressure and areas of low pressure. Fast moving air creates an area of low pressure because the particles are spread further apart while high pressure air has particles packed closer together.
Show and Tell: Hold two spoons by their handles, with their rounded backs facing each other and a small gap between them. Hold the spoons upside down under a sink tap. Turn on the tap so that a thin, steady stream of water flows. Hold the spoons close together and place them in the stream of water. The spoons will tend to move toward each other.
As water flows between the spoons, its movement creates a pressure difference between the water-filled gap and the surrounding water. The higher pressure outside the gap pushes the spoons toward each other.
Air Pressure and Flight: Differences in air pressure can create forces that affect how air and objects move.
A good example of this happens when a hole is made in the body of a passenger plane. The air in the plane is under high pressure to keep passengers comfortable compared to the low-pressure air outside. When a hole is made in the body of the plane, objects in the high-pressure plane move violently towards the low-pressure air outside, often resulting in disaster.
Show and Tell: Place a ping-pong ball on a flat surface. Bend down and blow air through a drinking straw toward the ball. Notice how the ball moves away from you.
Moving air can push against objects, causing them to move. Air also moves from areas of higher pressure toward areas of lower pressure when a pressure difference exists. Differences in air pressure help create the forces that act on airplane wings and explain how lift happens.
Newton’s Third Law: For every action there is an equal and opposite reaction.
This means, if there is a force in one direction, there is an equal force in the opposite direction. For example, when a person on a skateboard pushes backwards on the ground, they move forward. This law helps explain how rockets and jet engines work.
Show and Tell: Thread a string through a drinking straw and tie the string tightly between two chairs. Blow up a balloon, but do not tie it. Tape the balloon to the straw. Let go of the balloon and watch it move along the string.
As air rushes backward out of the balloon, the balloon pushes the air backward. The air pushes back with an equal and opposite force, moving the balloon forward. A jet engine pushes gases backward, which helps propel an airplane forward.
For more demonstrations of airflow, air pressure, and properties of gases, download the FREE worksheet
The Wing
The picture below shows a side view of a bird’s wing which is similar to the wing of a glider, airplane, or helicopter blade.
1. As an airplane moves forward, air flows over and under its wings.
2. The wing changes the direction of the moving air, and the air pushes against the wing.
3. As air flows around the wing, it creates differences in air pressure. During normal flight, the pressure is usually lower above the wing than below it.
4. This pressure difference helps create an upward force called lift, which helps the airplane stay in the air.
5. The shape of the wing, its angle, and how fast the airplane moves all affect how much lift the wing creates.
Test this concept with a hands-on activity to build a working model of a wing. Download the FREE worksheet for instructions and template.
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