A train is approaching towards a platform with a speed of 10 $m s^{- 1}$ while blowing a whistle of frequency $340 H z$ . What is the frequency of whistle heard by a stationary observer on the platform?
Given speed of sound = 340 $m s^{- 1}$ .

330 H z

No worries! We‘ve got your back. Try BYJU‘S free classes today!

350 H z

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

340 H z

No worries! We‘ve got your back. Try BYJU‘S free classes today!

360 H z

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is D $350 H z$
Speed of train (source) $v_{s o u r c e} = 10$ $m / s$
Original frequency of whistle $f_{o} = 340$ Hz
Speed of sound $v = 340$ $m / s$
Using Doppler's effect when a source moves towards the stationary observer :
Apparent frequency heard by observer $f = f_{o} [\frac{v}{v - v_{s o u r c e}}]$
$∴$ $f = 340 [\frac{340}{340 - 10}] = 350$ Hz

Suggest Corrections

Similar questions

Q. A train standing at a certain distance from a railway platform is blowing a whistle of frequency 500 Hz. If the speed of sound is

340 m s^{- 1}

, the frequency and wavelength of the sound of the whistle heard by a man running towards the engine with a speed of

10 m s^{- 1}

respectively are

Q. A train approaching a railway platform with a speed of

20 m s^{- 1}

, starts blowing the whistle. Speed of sound in air is

340 m s^{- 1}

. If the frequency of the emitted sound from the whistle is

640 H z

, the frequency of sound to a person standing on the platform will appear to be:

A train, standing at the outer signal of a railway station blows a whistle of frequency 400 Hz in still air. (i) What is the frequency of the whistle for a platform observer when the train (a) approaches the platform with a speed of $10 m s^{- 1}$ , (b) recedes from the platform with a speed of $10 m s^{- 1}$ ? (ii) What is the speed of sound in each case? The speed of sound in still air can be taken as $340 m s^{- 1}$

Q. An electric train in japan runs with a speed 1.3 Mach. It is approaching a station and blows a whistle of frequency 88 Hz. The frequency of the whistle heard by a stationary observer on the platform is :

Q. A boy blowing a whistle, is running away from a wall towards an observer with a speed of

1 m s^{- 1}

. The frequency of whistle is

680 H z

. The number of beats heard per second by the observer will be

(

given

v = 340 m s^{- 1})

Join BYJU'S Learning Program

A train is approaching towards a platform with a speed of 10 ms−1 while blowing a whistle of frequency 340Hz. What is the frequency of whistle heard by a stationary observer on the platform?Given speed of sound = 340 ms−1.

The correct option is D 350HzSpeed of train (source) vsource=10 m/sOriginal frequency of whistle fo=340 HzSpeed of sound v=340 m/sUsing Doppler's effect when a source moves towards the stationary observer :Apparent frequency heard by observer f=fo[vv−vsource]∴ f=340[340340−10]=350 Hz

A train is approaching towards a platform with a speed of 10 $m s^{- 1}$ while blowing a whistle of frequency $340 H z$ . What is the frequency of whistle heard by a stationary observer on the platform?
Given speed of sound = 340 $m s^{- 1}$ .