Home
Class 11
PHYSICS
A source of sound S is travelling at (10...


A source of sound S is travelling at `(100)/(3)(m)/(s)` along a road, towards a point A. When the source is 3 m away from A, a person standint at a point O on a road perpendicular to AS hears a sound of requency `v'`. The distance of O from A at that time is 4 m. If the original frequency is 640 Hz, then the value of `v'` is (velocity of sound is `340(m)/(s)`)

A

620 Hz

B

680 Hz

C

720 Hz

D

840 Hz

Text Solution

Verified by Experts

The correct Answer is:
B

Effective value of velocity of source is
`v_S=(100)/(3)costheta`
`=(100)/(3)xx(3)/(5)=20(m)/(s)`
`v'=(v)/(v-v_S)v`
`v'=(340)/(340-20)xx640Hz=680Hz`
Promotional Banner

Topper's Solved these Questions

  • SOUND WAVES AND DOPPLER EFFECT

    CENGAGE PHYSICS|Exercise Multiple Correct|44 Videos

  • SOUND WAVES AND DOPPLER EFFECT

    CENGAGE PHYSICS|Exercise Assertion-Reasoning|24 Videos

  • SOUND WAVES AND DOPPLER EFFECT

    CENGAGE PHYSICS|Exercise Subjective|56 Videos

  • RIGID BODY DYNAMICS 2

    CENGAGE PHYSICS|Exercise Interger|2 Videos

  • SUPERPOSITION AND STANDING WAVES

    CENGAGE PHYSICS|Exercise Comprehension Type|5 Videos

Similar Questions

Explore conceptually related problems

A statinary observer receives a sound of frequency 2000 Hz. The variation of apparent frequency and time is shown. Find the speed of source, if velocity of sound is 300(m)/(s)

A siren emiting sound of frequency 800Hz is going away from a static listence with a speed of 30 m//s frequency of sound to be beand by the listener is ("velocity of sound" = 330 m//s)

A siren emitting sound of frequency 800 Hz is going away from a static listener with a speed of 30 m/s. Frequency of the sound to be heard by the listener is ( Take velocity of sound as 300 m/s )

A source and an observer move away from each other with a velocity of 10 m/s with respect to ground. If the observer finds the frequency of sound coming from the source as 1950 Hz , then actual frequency of the source is (velocity of sound in air = 340 m/s )

A man standing on a platform hears the sound of frequency 604 Hz coming from a frequency 550 Hz from a train whistle moving towards the platform. If the velocity of sound is 330 m/s, then what is the speed of train?

A source emits sound of frequency 600Hz inside water. The frequency heard in air will be equal to (velocity of sound in water =1500(m)/(s) , velocity of sound in air=300(m)/(s))

.A source is moving with a constant speed of "10m/s" on a circular track of "200m" .It emits a sound of frequency "200Hz" .A listener stands at the centre of the circular track.The frequency recieved by the listener is (velocity of sound "=340m/s" ) 1) zero 2)200Hz 3)190Hz 4) 210Hz

A source of sound and a listener are moving towards each other . The velocity of the source is 20 m s^(-1) and that of the observer is 15 m s^(-1) . If the velocity of sound is 340 m s^(-1) and its frequency is 640 Hz, find the apparent frequency of the sound .

A source of frequency 150 Hz is moving in the direction of a person with a velocity of 110 m / s . The frequency heard by the person will be (speed of sound in medium = 330 m / s )

CENGAGE PHYSICS-SOUND WAVES AND DOPPLER EFFECT-Single Correct
  1. A source of sound produces waves of wavelength 60 cm when it is statio...

    Text Solution

    |

  2. The apparent frequency of the whistle of an engine changes in the rati...

    Text Solution

    |

  3. A source of sound S is travelling at (100)/(3)(m)/(s) along a road, to...

    Text Solution

    |

  4. A source of sound is travelling with a velocity of 30(m)/(s) towards a...

    Text Solution

    |

  5. A source of sound emits 200piW power which is uniformly distributed ov...

    Text Solution

    |

  6. Two cars are moving on two perpendicular roads towards a crossing with...

    Text Solution

    |

  7. A tuning fork of frequency 380 Hz is moving towards a wall with a velo...

    Text Solution

    |

  8. A sound wave of frequency n travels horizontally to the right with spe...

    Text Solution

    |

  9. A boy is walking away from a well at a speed of 1.0 m//s in a directio...

    Text Solution

    |

  10. A source emitting a sound of frequency v is placed at a large distance...

    Text Solution

    |

  11. Due to a point isotropic sonic source, loudness at a point is L=60dB I...

    Text Solution

    |

  12. The frequency of a car horm is 400 Hz. If the horn is honked as the ca...

    Text Solution

    |

  13. Spherical sound waves are emitted uniformly in all direction from a po...

    Text Solution

    |

  14. When a person wears a hearing aid, the sound intensity level increases...

    Text Solution

    |

  15. A motorcycle starts from rest and accelerates along a straight line at...

    Text Solution

    |

  16. The difference in the speeds of sound in air at -5^@C, 60 cm pressure ...

    Text Solution

    |

  17. A train is moving in an elliptical orbit in anticlockwise sense with a...

    Text Solution

    |

  18. A stationary observer receives a sound from a sound of freqeuency v0 m...

    Text Solution

    |

  19. The sound from a very high burst of fireworks takes 5 s to arrive at t...

    Text Solution

    |

  20. A car emitting sound of frequency 500 Hz speeds towards a fixed wall a...

    Text Solution

    |