Question

The velocity of sound in air is $330m{s}^{-1}$. To increase the apparent frequency of the sound by $50\%,$ the source should move towards the stationary source with a velocity equal to

• A. $110{\text{ms}}^{-1}$
• B. $105{\text{ms}}^{-1}$
• C. $220{\text{ms}}^{-1}$
• D. $330{\text{ms}}^{-1}$

Answer 1

Answer: (A)

$110{\text{ms}}^{-1}$

$\frac{n^{\prime }}{n_0}=\frac{V}{V-V_s}=1.5$,

$\frac{330}{330-V_s}=1.5$,

$V_s=110m{s}^{-1}$

option "A" is correct.