Newton's Third Law of Motion: For every action, there is an equal and opposite reaction.
How it applies to airplanes:
1. The Action: The plane's engines push air backwards. This is the action force.
2. The Reaction: The air, in turn, pushes the plane forward with an equal and opposite force. This is the reaction force.
Let's break it down:
* The Engines: Airplane engines create thrust by compressing and accelerating air. They push this air backwards, creating a high-speed jet of air.
* The Wings: The wings are shaped to create a difference in air pressure above and below them. This difference in pressure, called lift, pushes the plane upwards.
* The Third Law: The air being pushed backwards (action) by the engines creates an equal and opposite force (reaction) that propels the plane forward. This forward force is called thrust.
Key Points:
* Lift: Lift is the force that opposes gravity and allows the plane to stay in the air. It's generated by the shape of the wings.
* Thrust: Thrust is the force that propels the plane forward. It's generated by the engines.
* Drag: Drag is the force that opposes the plane's motion. It's caused by friction between the air and the plane's surfaces.
* Weight: Weight is the force of gravity acting on the plane.
In Summary:
An airplane flies by using the third law of motion to create thrust, which propels the plane forward. The wings generate lift, which counteracts gravity. The plane stays in the air because the lift generated by the wings is greater than the plane's weight.
