## Question

A source of sound of frequency 256 Hz is moving towards a wall with a velocity of 5 m/s. Velocity of sound is 330 m/s. The number of beats per second heard by an observer standing between the source and the wall is nearly:

### Solution

In this case, the observer stands between the source and the reflecting wall. For the direct sound, the frequency *n’* is given by:

As the echo source also moves towards the observer,

#### SIMILAR QUESTIONS

An observer is moving with velocity *v*_{0} towards a stationary sound source emitting waves of frequency *n*. If *v* is the velocity of sound waves, then the wavelength of the sound waves as detected by the observer will be:

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A source of sound of frequency 256 Hz is moving towards a wall with a velocity of 5 m/s. The velocity of sound is 330 m/s. The number of beats heard by an observer moving along with the sounding object is: