Here's why:
* Newton's Law of Universal Gravitation: This law states that every object in the universe attracts every other object with a force that is:
* Directly proportional to the product of their masses: The more massive the objects, the stronger the gravitational force.
* Inversely proportional to the square of the distance between their centers: The farther apart the objects, the weaker the gravitational force.
* Airplane and Earth: The Earth has a much larger mass than an airplane. This means the gravitational force between the Earth and the airplane is significant, pulling the airplane downwards.
* Counteracting Gravity: Airplanes don't fall straight to the ground because their wings generate lift, which opposes gravity. This lift force is generated by the shape of the wings and the movement of air over and under them.
