Question 151: Waves

Question

An observer moves towards a stationary source of sound with a velocity equal to one-fifth of the velocity of sound. The percentage change in the frequency will be :

Accepted Answer

$$f' = {f_0}\left[ {{{v - {v_0}} \over {v - {v_s}}}} \right]$$
$$ \Rightarrow f' = {f_0}\left[ {{{v + {v \over 5}} \over v}} \right]$$
$$ \Rightarrow f' = {{6{f_0}} \over 5}$$
$$\Rightarrow$$ % change = 20

Answer

20%

Answer

10%

Answer

5%

Answer

0%

Waves

An observer moves towards a stationary source of sound with a velocity equal to one-fifth of the velocity of sound. The percentage change in the frequency will be :

Choose the correct answer: