Missing figure: find it in attachment.
Answer:
Force D
Explanation:
In order to answer the question, let's keep in mind that the force of gravity on an object on Earth is the attractive force exerted by the Earth on the object; its direction is always downward (towards the Earth's centre), and its magnitude is given by
F = mg
where m is the mass of the object and g is the acceleration of gravity.
It follows immediately that in the figure, the force of gravity is the only force acting downward: therefore, force D.
The other forces are called:
Force A: thrust (it is the forward force generated by the engines)
Force B: lift (it is the upward produced by the aerodynamics of the wings)
Force C: air resistance (it is the backward force due to the friction between the air and the surface of the plane)
