Which of the following statements is true regarding lift?

Which of the following statements is true regarding lift?

• A. It is always constant at all speeds
• B. It acts opposite to drag
• C. It can decrease sharply at high angles of attack
• D. It is unaffected by wing design

Answer: (C)

Lift is a critical aerodynamic force that varies with various factors, including angle of attack. When an aircraft's wing reaches high angles of attack, the airflow over the wing can become disturbed, leading to a condition known as stall. This phenomenon causes a significant and abrupt decrease in lift, as the smooth airflow separates from the wing's surface. Therefore, at high angles of attack, the relationship between lift and angle becomes non-linear, and the lift can sharply decrease, making this statement true. In contrast, lift is not constant at all speeds or conditions; it varies based on speed, air density, and wing design. While lift acts in the opposite direction to weight and contributes to overcoming drag, this does not mean it directly opposes drag. Similarly, wing design significantly influences lift characteristics, including maximum lift coefficient and stall behavior. Therefore, the nuanced effects of angle of attack on lift are emphasized in the context of this question.

Lift is a critical aerodynamic force that varies with various factors, including angle of attack. When an aircraft's wing reaches high angles of attack, the airflow over the wing can become disturbed, leading to a condition known as stall. This phenomenon causes a significant and abrupt decrease in lift, as the smooth airflow separates from the wing's surface. Therefore, at high angles of attack, the relationship between lift and angle becomes non-linear, and the lift can sharply decrease, making this statement true.

In contrast, lift is not constant at all speeds or conditions; it varies based on speed, air density, and wing design. While lift acts in the opposite direction to weight and contributes to overcoming drag, this does not mean it directly opposes drag. Similarly, wing design significantly influences lift characteristics, including maximum lift coefficient and stall behavior. Therefore, the nuanced effects of angle of attack on lift are emphasized in the context of this question.