A simple piece of paper will fall down when dropped, but if we fold the same piece of paper in a specific manner, it will fly.
How do paper planes fly?
The ability to fly means the ability of an object to move or travel through air. There are four things that decide if an object is going to fly or not. Any change in these same factors also decide how fast it will fly or how fast it will fall.
What are the forces that prevent an object from flying?
Forces that prevent an object from flying are :
- The weight force downwards: The heavier the object, the greater the force of gravity that pulls it down. That is why when we want to make things fly, we make them as light as possible. This is how weight affects the flight of the airplane.
- The drag force: Drag is the force that is exerted in the opposite direction that the object is pushed in. It increases as the speed increases. In airplanes, drag is caused by the air surrounding the airplane.
The field which studies the interaction between the air and the moving object is called aerodynamics. The study of aerodynamics is important when designing airplanes and other objects moving through the wind. It is even used when designing trucks and trains.
- The thrust upwards: The thrust upwards has to always be more or equal to the thrust downwards or the object will fall down. In airplanes when the plane moves in the air, the wing is designed in such a way that the air it is cutting through, is pushing the plane up. In helicopters, the thrust is generated by rotor blades that push the air downwards like a fan.
- The thrust forward: The thrust forward pushes the plane forward. This pushes the airplane in a given direction. If the thrust forward is more than the drag force, the plane increases in speed. If the thrust is less then the drag, the plane decreases in speed. In large airplanes both thrust and force is generated by propellers or jet engines.
How far do paper planes fly?
The current world record for the distance a paper plane has flown is around 225 feet! Not bad for a folded piece of paper!