Home
Class 12
PHYSICS
A SONAR system fixed in a submarine ope...

A SONAR system fixed in a submarine operates at a frequency40.0 kHz. An enemy submarine moves towards the SONAR with a speed of `360km h^(-1)`.What is the frequency of sound reflected by the submarine? Take the speed of sound in water to be `1450ms^(-1)`

Text Solution

Verified by Experts

Here, frequency of SONAR,
`v=40 KHz =40 xx 10^(3) Hz`
Speed of observer `//` enemy's submarine
`v_(1) = 360 km//h`
`= 360xx ( 5)/( 18) m//s = 100 m//s `
Speed of sound wave in water,`v= 1450 m//s`. As the source is at rest & observer is moving towards the source , therefore, apparent frequency receivedby enemy submarine.
`v^(1) = ((v+ v_(l))v)/(v)`
`((1450+100)40 xx10^(3)Hz)/(1450)`
`= 4.27 xx10^(4) Hz`
This frequency is reflected by enemy submarine ( source) and is observed by SONAR . Therefore in this case.
`v_(s) =360 km//s= 100 m//s , v_(l) = 0`
` :. ` Apparent frequency , `v^(11)= (vxx v)/(v-v_(s))`
`= ( 1450 xx 4.276 xx10^(4))/(1450-10)`
`= 4.59 xx 10^(4) Hz= 45.9Hz`
Promotional Banner

Topper's Solved these Questions

  • WAVES

    VIKRAM PUBLICATION ( ANDHRA PUBLICATION)|Exercise TEXTUAL EXERCISES|21 Videos

  • WAVE OPTICS

    VIKRAM PUBLICATION ( ANDHRA PUBLICATION)|Exercise Problems|6 Videos

Similar Questions

Explore conceptually related problems

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

A siren emitting a sound of frequency 1000 Hz moves away from you towards a cliff at a speed of 10 m/s. (a) What is the frequency of the sound you hear coming directly from the siren ? (b) What is the frequency of the sound you hear reflected off the cliff (c) What beat frequency would you hear ? Take the speed of sound in air as, 330 m/s.

A SONAR (sound navigation and ranging) uses ultrasonic waves to detect and locate objects under water. In a submarine equipped with a SONAR , the time delay between generation of a probe wave and the reception of its echo after reflection from an enemy submarine is found to be 77.0s. What is the distance of the enemy submarine ? (Speed of sound in water = 1450 ms^(-1)) .

A car with a horn of frequency 620 Hz, travels towards a large wall with a speed 20ms^-1 . If velocity of sound is 330ms^-1 the frequency of echo of sound of horn as heard by driver

A source producing sound of frequency 170 Hz is approachig a stationary observed with a velocity of 17ms^-1 . The apparent change in the wavelength of sound heard by the observer is (speed of sound in air = 340ms^-1 )