Which of the following, when doubled, will cause the greatest increase in lift?

Doubling the velocity will cause the greatest increase in lift due to the relationship described in the lift equation, which states that lift is proportional to the square of the velocity. The lift equation is typically expressed as:

[ L = \frac{1}{2} \times \rho \times V^2 \times S \times C_L ]

Where:

• ( L ) is the lift force,

• ( \rho ) is the air density,

• ( V ) is the velocity of the aircraft,

• ( S ) is the wing area,

• ( C_L ) is the coefficient of lift.

When velocity is doubled, since lift is proportional to the square of the velocity, the resulting increase in lift is not just double but quadrupled. Specifically, if the original velocity ( V ) is increased to ( 2V ), the lift would increase to:

[ L' = \frac{1}{2} \times \rho \times (2V)^2 \times S \times C_L = \frac{1}{2} \times \rho \times 4V^2 \times S \times C_L = 4L ]

This means the lift increases by a factor