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BITSAT2020PhysicsWaves and SoundActual

A whistle of frequency 1000 ~Hz is sounded on a car travelling towards a cliff with velocity of 18 ~m ~s ⁻¹ normal to the cliff. If c =330 ~m ~s ⁻¹ , then the apparent frequency of the echo as heard by the car driver is nearly

Options

  1. A1115 ~Hz
  2. B115 ~Hz
  3. C67 ~Hz
  4. D47.2 ~Hz

Correct answer

A. 1115 ~Hz

Step-by-step solution

By the concept of accoustic, the observer and source are moving towards each other, each with a velocity of 18 ~m ~s ⁻¹ v ^ = 330+18 330-18 1000 1115 ~Hz

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