Final answer:
In order to take off, the aircraft's lift and thrust must be sufficient to overcome its weight and drag.
Step-by-step explanation:
In order to take off, the aircraft's lift and thrust must be sufficient to overcome its weight and drag. The lift force is generated by the wings as they move through the air, and it must be greater than or equal to the weight of the aircraft for it to take off. The thrust force is provided by the engines and it must be greater than or equal to the drag force, which is the resistance encountered by the aircraft as it moves through the air.
For example, when an airplane is taking off, the engines provide a thrust force to push the plane forward. At the same time, the wings generate lift force by creating a pressure difference between the upper and lower surfaces of the wings. This lift force counters the weight of the aircraft, allowing it to become airborne.