Home
Class 12
PHYSICS
A person B accidentally slips from a lar...

A person B accidentally slips from a large building and screams with a sound of constant frequency v as he falls as shown in the figure. What will be apparent frequency of the second of the scream as heard by the person A, at the top of the building as a function of time?

A

`v'=v(v/(v-"gt"))`

B

`v'=v(v/(v+"gt"))`

C

`v'=v((2v)/(2v-"gt"^(2)))`

D

`v'=v((2v)/(2v-"gt"^(2)))`

Text Solution

Verified by Experts

The correct Answer is:
B
The person B moves away from person A
or the source o f sound moves away from A.
Hence the apparent frequency is
`v.=v_(0)(v/(v+v_(s)))v_(0)`
Where `v_(B)` is the speed of sound and `v_(B)` is the speed of the person `B` (source) since (from `v=u+at` and u=0)
`v_(B)="gt"`
we get `v.=v_(0)(v/(v+"gt"))`
Promotional Banner

Topper's Solved these Questions

  • NTA TPC JEE MAIN TEST 69

    NTA MOCK TESTS|Exercise PHYSICS|30 Videos

  • NTA TPC JEE MAIN TEST 71

    NTA MOCK TESTS|Exercise PHYSICS|30 Videos

Similar Questions

Explore conceptually related problems

A scooterist moves towards a vertical wall with a speed of 54 km h^(-1) . A person is standing on the ground and is behind the scooter , hears the sound . If the scooterist sounds the horn of frequency 400 Hz , calculate the apparent frequency sound heard by the person when (a) It is coming directly from the horn. (b) coming after reflection from the vertical wall. (Take speed of sound to be 330 m s^(-1) )

An ambulance fitted with a siren of v = 400 Hz is going towards a vertical wall at a speed of 54 km/hr. A person standing on the road, behind the ambulance, listens to the siren sound coming from the ambulance as well as that coming after reflection from the wall. Calculate the apparent frequency of the sound wave (a) directly coming from the siren to the person, and (b) coming after reflection from the wall Take, speed of sound = 340 m/s

A car is moving along X-axis with a velocity v=20m//s . It sounds a whistle of frequency 660 Hz. If the speed of sound is 340m//s . The apparent frequency heard by the observer O (shown in figure) is:

The horn of a car emits sound with a dominant frequency of 2400 Hz. What will be the apparent dominant frequency heard by a person standing on the road in front of the car if the car is approaching at 18.0 km h^-1 ? Speed of sound in air = 340 m s^-1

A train whistling at constant frequency is moving towards a station at a constant speed V. The train goes past a stationary observer on the station. The frequency n^(') of the sound as heard by the observer is plotted as a function of time t, figure. Identify the expected curve.

Two cars are approaching each other on a straight road and moving with a velocity of 30 kmh-1 . If the sound produced in a car is of frequency 500 Hz, what will be the frequency of sound as heard by the person sitting in the other car ? When the two cars have crossed each other and are moving away from each other, what will be the frequency of sound as heard by the same person ? Speed of sound= 330 ms^-1 .

In a series LCR circuit the phasors corresponding to voltage across resistance, capacitor and inductor at an instant are as shown in the Figure and have amplitudes of V_(RO) = 4 "volt", V_(CO) = 3 "volt", and V_(LO) = 6 "volt" (a) Is the source frequency larger than or lesser than the resonance frequency? Does the current (I) lead or lag the source voltage? (b) Find the voltage amplitude of the source. (c) If VR phasor makes theta=53^(@) at time t = 0, write the source voltage as function of time. Take angular frequency of the source to be omega[sin53^(@)=(4)/(5)]

A particles is projected horizontally with a speed v from the top of a plane inclined at an angle tehta to the horizontal as shown in the figure. (a) Hwo far from the point of projection will the particle strike the plane ? (b) Find the time taken by the particel to hit the plane. (c) What is the velocity of particle just before it hits the plane ?

NTA MOCK TESTS-NTA TPC JEE MAIN TEST 70-PHYSICS
  1. One mole of O(2) gas is contained in a box of volume V=2m^(3) at press...

    Text Solution

    |

  2. Choose the incorrect stateement about relative magnetic permeability:

    Text Solution

    |

  3. A person B accidentally slips from a large building and screams with a...

    Text Solution

    |

  4. A new unit of length is chosen such that the speed of light in vecuum ...

    Text Solution

    |

  5. A drop of water of radius 0.0015 mm is falling in air .If the coeffici...

    Text Solution

    |

  6. Three lenses of focal length +15cm,+150 cm and +250 cm are available, ...

    Text Solution

    |

  7. The moment of inertia of a body depends upon

    Text Solution

    |

  8. A slab X of thickness 't', thermal conductivity 'K' and area of cross-...

    Text Solution

    |

  9. A Carno'ts heat engine working between the temperature limits 400 K an...

    Text Solution

    |

  10. Two periodic waves of intensities I(1) and I(2) pass through a region ...

    Text Solution

    |

  11. Water is faling on the blades of a turbie at a rate of 300 kg"minute"^...

    Text Solution

    |

  12. A 36 W ultraviolet light source eits light of wavelength 2200Å. This l...

    Text Solution

    |

  13. In a sereis L-C-R circuit, C = 10^(-11) Farad, L = 10^(-5) Henry and R...

    Text Solution

    |

  14. A parallel plate capacitor is made of two circular plates separated by...

    Text Solution

    |

  15. Find the value of b if a unit vector is represented as (0.8hati+bhatj+...

    Text Solution

    |

  16. A man of 80 kg fastns a rope to a mass of 120kg, and passes the rope ...

    Text Solution

    |

  17. A coil in the shape of an equilateral triangle of side l is suspended ...

    Text Solution

    |

  18. Two tuning forks are known to have frequency 258Hz and 264 hz and a ma...

    Text Solution

    |

  19. A block of mass m is connected with two ideal pullies and a massless s...

    Text Solution

    |

  20. Consider a wire suspended vertically from a rigid support. A load is n...

    Text Solution

    |