STEM Takes Flight: Science and Aircrafts
If you've ever thought about huge and heavy aircraft taking off from the ground and flying through the sky, you've been pondering the science behind flying. It may seem impossible for something as heavy as an airplane to lift off of the ground and fly, but this happens thanks to several different forces that work to make flight possible. The forces that work together to allow airplanes to fly include lift, thrust, drag, and weight.
Airplane Forces
Sir Isaac Newton discovered laws of motion that help people understand how flight is possible. Newton's first law is about inertia, or how objects move or don't move. This law states that an object will stay unmoving or it will keep moving in a straight line unless another force changes this course. Newton's second law is about how the speed at which an object moves will change if an external force is applied. Newton's third law states that every force has an equal force with an opposite reaction. Newton's third law applies to the forces of lift and thrust, which are responsible for moving airplanes. Aircraft must have lift and thrust to move up and forward from the ground. An airplane engine is responsible for the power of the thrust. The force of drag happens as the air resists against the airplane moving forward. The forces of lift and weight work against each other. The lift comes mostly from the wings, and it has to be more than the airplane's weight to get the airplane off of the ground.
Bernoulli's Principle
Daniel Bernoulli was a scientists in the 1700s, and he studied how fluid moves. Air is technically a fluid because it can conform to different shapes and it flows, so Bernoulli's principle also applies to the way air moves. Bernoulli's principle states that when a flow of fluid moves horizontally, the points with higher fluid speed have less pressure than the points with slower fluid speed. Airplane wings are shaped to cause air to pass over and under them at different speeds. Air moving over the tops of airplane wings is faster, which decreases the air pressure. Air beneath the wings moves straight, so the speed and pressure stays relatively constant. High pressure continuously moves toward low pressure, so air beneath the wings pushes upward to create lift.
Engineering of Aircraft
Airplanes have many different parts that work together to enable flight. Airplane engines move the aircraft forward, giving it thrust. As the plane moves forward, air moves quickly over the wings, creating lift. As long as this lift is stronger than the weight of the airplane, the plane will move up and off of the ground, and it will stay in the air. To fly an airplane, a pilot steers the plane by tilting it to one side or the other. Tilting the plane involves dipping one wing below the level of the other wing, which causes the plane to steer into a curve. Steering into a curve causes less lift, which will result in a loss of altitude. But the pilot can fix this by adjusting parts called elevators that are located at the back of the plane.
Experiments and Games
Although the scientific laws of motion and flight can seem complicated, these can be fun lessons to learn. Try conducting experiments to see how the laws of motion work. A simple experiment involves bouncing two balls of different sizes together. Placing the smaller ball on top of the larger ball will cause energy to transfer from the bigger ball to the smaller ball. You can also play games to get a better idea of how flight happens.
