Home
Class 11
PHYSICS
A fighter plane moving in a vertical loo...

A fighter plane moving in a vertical loop with constant speed of radius `R` . The center of the loop is as a height `h` directly overhead of an observer standing on the ground. The observer receives maximum frequency of the sound produced by the plane when it is nearest to him . Find the speed of the plane. Velocity of sound in air is `upsilon` .

Text Solution

Verified by Experts

The correct Answer is:
A, B
Let the speed of the plane (source ) be `upsilon_(s)`. Maximum frequency will be observed by the observer when `upsilon_(s)` is along `SO`. The observer recives maximum frequency when the plane is nearest to him . That is as soon as the wave pluse reaches from `S` to `O` with speed `upsilon` the plane reaches from `S` to `S'` with speed `upsilon_(s)`. Hence,

`t = (SO)/(upsilon) = (SS')/(upsilon_(s))` or `upsilon_(s) = ((SS')/(SO))upsilon`
= `(R theta)/sqrt(h^(2) - R^(2)) upsilon`
Here, `cos theta= (R)/(h)` or `theta = cos^(-1) ((R)/(h))`
Promotional Banner

Topper's Solved these Questions

  • SOUND WAVES

    DC PANDEY|Exercise Level 1 Assertion And Reason|10 Videos

  • SOUND WAVES

    DC PANDEY|Exercise Level 1 Objective|34 Videos

  • SOUND WAVES

    DC PANDEY|Exercise TYPE 5.|2 Videos

  • SOLVD PAPERS 2017 NEET, AIIMS & JIPMER

    DC PANDEY|Exercise Solved paper 2018(JIPMER)|38 Videos

  • SUPERPOSITION OF WAVES

    DC PANDEY|Exercise Level 2 Subjective|8 Videos

Similar Questions

Explore conceptually related problems

An observer standing on a railway crossing receives frequencies 2.2 kHz and 1.8 kHz when the tran approaches and recedes from the observer. Find the velocity of the train (speed of sound in air is 300 m/s).

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)

The ratio of the apparent frequencies of a car when approaching and receding a stationary observer is 11:9 What is the speed of the car, if the velocity of sound in air is 330 m/s?

A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff at a speed of 15ms^-1 . Then the frequency of sound that the observer hears in the echo reflected from the cliff is (Take velocity of sound in air =330ms^-1 )

A source emitting sound at frequency 4000 Hz, is moving along the Y-axis with a speed of 22 m s^-1 . A listener is situated on the ground at the position (660 m, 0). Find the frequency of the sound received by the listener at the instant the source crosses the origin. Speed of sound in air = 330 m s^-1 .

An aeroplane flying horizontally makes a sound when its angle of elevation w.r.t a person on ground is theta . But the sound reached the person, when the aeroplane was just over him. Find the mach.no. of the aeroplane. Also find its speed if speed of sound in air is 'v'_(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 supersonic jet plane moves parallel to the ground at speed v= 0.75 mach (1 mach = speed of sound). The frequency of its engine sound is v_0= 2kHz and the height of the jat plane is h= 1.5 km. At some instant an observer on the ground hears a sound of frequency v= 2v_0 . Find the instant prior to the instant of hearing when the sound wave received by the observer was emitted by the jet plane. Velocity of sound wave in the condition of observer =340 m"/"s .