Question

At what speed should a source of sound move so that observer finds the apparent frequency equal to half of the original frequency

• A. v / 2
• B. 2v
• C. v / 4
• D. v

Answer 1

Answer: (D)

v

Answer 2

$n' = \frac{v}{v + v_{s}}.n$ ⇒ $\frac{n}{2} = \frac{v}{v + v_{s}}.n$ ⇒ v_s = v