Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • NCERT
  • A train, standing in a station yard, blows a whistle of frequency 400 Hz in still air. The wind starts blowing in the direction from the yard to the station with a speed of 10 m/s. Given that the speed of sound in still air is 340 m/s

A train, standing in a station yard, blows a whistle of frequency 400 Hz in still air. The wind starts blowing in the direction from the yard to the station with a speed of 10 m/s. Given that the speed of sound in still air is 340 m/s

a) the frequency of sound as heard by an observer standing on the platform is 400 Hz

b) the speed of sound for the observer standing on the platform is 350 m/s

c) the frequency of sound as heard by the observer standing on the platform will increase

d) the frequency of sound as heard by the observer standing on the platform will decrease

 

Answers (1)

The answer is the option (a) and (b)    Frequency of source of sound v_{0}=400 Hz

 The velocity of wind from source

v_{w}=\frac{10m}{s} 

 Speed of sound in still air

v=\frac{340m}{s}

  Now, the speed of sound with respect to the listener

v+v_{w}=340+10=\frac{350m}{s}

As the distance between listener and source does not change, so the frequency of sound does not change as heard by the listener.

Posted by

infoexpert24

View full answer

Similar Questions

Latest Question