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JEE Main202124 Feb 2021Evening ShiftPhysicsWaves and SoundActual

Two cars are approaching each other at an equal speed of 7 . 2 km hr - 1 . When they see each other, both blow horns having a frequency of 676 Hz . The beat frequency heard by each driver will be _______ Hz . [Velocity of sound in air is 340 m s - 1 .

Correct answer

0

Step-by-step solution

Frequency of sound heard by car- 1 , which comes by reflection from car- 2 f 1 = f 0 340 + 2 340 - 2 340 + 2 340 - 2 = f 0 342 338 2 Frequency of sound coming directly from car- 2 f 2 = f 0 340 + 2 340 - 2 ∴     f 1 - f 2 = f 0 342 338 342 338 - 1 = 8 . 09 ≃ 8   Hz

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