Physics Problem with Lifting Force and Drag Coefficient

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The discussion revolves around calculating the lifting force and drag coefficient for an aircraft designed in 2014, with specific parameters including a top speed of 812 m/s and a mass of 72,000 kg. Participants express confusion about the concept of lifting force, particularly whether it is equivalent to the weight of the aircraft. The drag coefficient formula is provided, but users seek clarification on how to apply it without knowing the surface area. Additionally, there is a request for a free body diagram to better understand the forces acting on the aircraft during level flight. Overall, the focus is on grasping the fundamental principles of aerodynamics related to lifting and drag.
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Homework Statement


Flying aircraft X is designed in 2014. The current model has a top speed of 812 m/s, a mass of 72,000 kg when fully loaded, and a maximum thrust to weight ratio of 0.44. Calculate the lifting force and the drag coefficient for the Quinjet when it is flying level at top speed. Assume turbulent flow.

Homework Equations


Drag Coefficient: Fd = cd 1/2 ρ v2 A

The Attempt at a Solution


I do not understand how lifting force work(teacher didn't bother to teach us before assigning the homework) and can only calculate drag coefficient given the surface area.
 
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Can you draw a free body diagram of an aircraft in level flight at constant velocity? What is the lifting force equal to?
 
billy_joule said:
Can you draw a free body diagram of an aircraft in level flight at constant velocity? What is the lifting force equal to?
Is the lifting force just equal to the weight?
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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