An airplane is traveling in level flight at a constant velocity. L is the lift, W is the weight, T is the thrust, and D is the drag. Which of the diagrams is the correct free-body force diagram for the airplane?
A) Figure 1
B) Figure 2
C) Figure 3
D) Figure 4
E) Figure 5

Question

An airplane is traveling in level flight at a constant velocity. L is the lift, W is the weight, T is the thrust, and D is the drag. Which of the diagrams is the correct free-body force diagram for the airplane? 
A) Figure 1 
B) Figure 2 
C) Figure 3 
D) Figure 4 
E) Figure 5

Quizplus · Accepted Answer

In level flight, the airplane is traveling at a constant velocity, so the forces must be balanced. The weight (W) of the airplane is balanced by the lift (L) generated by the wings, and the thrust (T) of the engines is balanced by the drag (D) of the airplane moving through the air. The free-body force diagram in Figure 2 correctly represents this balance of forces.

An Airplane Is Traveling in Level Flight at a Constant