Question

A source of 300 Hz frequency, an observer and a wind are moving as shown in the figure with respect to the ground. The frequency heard by observation is ______.

 

(Take, the speed of sound in air = 340 m/s)

Options

• 274 Hz

• 282.6 Hz

• 308.45 Hz

• 327.7 Hz

Answer 1

A source of 300 Hz frequency, an observer and a wind are moving as shown in the figure with respect to the ground. The frequency heard by observation is 274 Hz.

Explanation:

The frequency observed by the observer is given by,

`f = ("v" - "v"_"w" - "v"_"o")/("v" - "v"_"w" + "v"_"s") xx f_o = (340 - 5 - 20)/(340 - 5 + 10) xx 300`

f = 274 Hz