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Most Important Selected Qs for JEE AdvancedPhysicsWaves and Sound

At a particular instant a source of sound of frequency 100 Hz is at (2 ~m , 1 ~m ) and an observer is at (5 ~m , 5 ~m ) . The velocity of source and observer are 15(2 i + j ) m / s and 5 i +15 j ~m / s respectively at this instant .The velocity of sound in air is 330 ~m / s . Find the frequency of sound (in Hz ) received by the observer.

Correct answer

105

Step-by-step solution

S O =4 i +4 j Component of velocity along SO aligned & v_s=15(2 i + j ) ( 3 i +4 j 5 )=30 & v₀=(5 i +15 j ) ( 3 i +4 j 5 )=15 & f= 330-15 330-30 100=105 ~Hz aligned

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