1. Gravity: This force pulls the object downwards towards the Earth's center. It's always present and constant.
2. Thrust: This is the force that propels the object forward, generated by engines or other means of propulsion.
3. Lift: This force acts perpendicular to the direction of motion and opposes gravity. It's generated by the shape of the object and its interaction with the air.
4. Drag: This force opposes the object's motion, acting in the opposite direction of travel. It's caused by friction between the object and the air.
Therefore, the four forces of aerodynamics are lift and drag, which specifically describe the interaction between an object and the air it moves through.
It's important to remember that thrust and gravity are also essential components of flight, as they affect the overall motion and balance of an object in the air.
