How does speed increase impact drag?

Drag in aviation is significantly influenced by speed, and as aircraft speed increases, the resistance or drag force encountered by the aircraft grows. This relationship follows a specific mathematical principle; in most aerodynamic conditions, drag increases with the square of the speed. This means that if the speed of the aircraft doubles, the drag increases by a factor of four. Consequently, this quadratic relationship is the key reason why option B is the correct choice.

This effect arises from the principles of fluid dynamics, where the drag force can be expressed using the equation for drag, which incorporates the velocity squared term. As the speed of the aircraft rises, the kinetic energy of the air around it also increases, leading to more turbulence and a greater drag force.

The other options do not hold true due to the nature of drag. The idea that drag decreases linearly does not align with physical behavior, as drag does not reduce simply as speed increases. The premise that drag remains constant regardless of speed overlooks the fundamental changes that occur in the airflow dynamics around the aircraft with varying speeds. Lastly, while altitude can have effects on air density and, consequently, drag, the statement that drag is unaffected by altitude is misleading, as changes in altitude can lead to varying drag characteristics. Thus, understanding this