Answer:
D. gravity, friction, and an applied force
Explanation:
The force of gravity is the force of attraction that gravity exerts on the bodies that are on the surface of the Earth. In the case of the plane, the force of gravity opposes its lifting, both on the ground and in flight.
On the other hand, the frictional force is that which opposes the movement of objects that are submerged in a fluid, in this case, air is considered a fluid, being a gas. The aerodynamic friction force, opposes the displacement of the aircraft when they travel through it, and depends on the shape and roughness of the plane's surface, as well as the density of the air
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The applied force is provided by the airplane's engine through the propeller. This force allows the plane to move through the air and is opposite to the frictional force. For the aircraft to maintain this force it must be equal to the friction force.