How does the forces thrust,lift,drag and gravity actupon an airplane in flight?

Answer 1

thrust has to do with the speed of the aircraft,creating enough speed to achieve lift.The wing gets lift by air traveling faster under the wing than on top of it.Drag is used to stabilize the aircraft(ailerons etc.)gravity is what happens when you slow down the aircraft,creating less lift(air under the wings)

Answer 2

Here you go:

Trust - forward momentum
Lift - the force against the underside of wing for flight
Drag - the force pushing against the forward momentum
Gravity - the force pushing downward, toward the center of earth.

All these are critical for an airplane to fly and land. One without the other would be disasterous. In this combination, an airplane can safely take off, fly, and land.