Question

An unpowered glider is flying at a glide angle of 10 degrees. Its lift-to-drag ratio is _________ (round off to two decimal places).

Hint:

Smaller glide angles always correspond to higher lift-to-drag ratios.

Answer 1

Correct Answer: 5.55

For a glider, \[ \frac{D}{L}=\tan\gamma \quad \Rightarrow \quad \frac{L}{D}=\frac{1}{\tan\gamma}. \] Given \(\gamma=10^\circ\): \[ \tan 10^\circ \approx 0.1763. \] Thus, \[ \frac{L}{D}=\frac{1}{0.1763}\approx 5.67. \]