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Olympiad workbookNSEPWaves and Sound

A police car, moving at speed of 108 ~km / hour, approaches a truck moving at 72 ~km / hour in opposite direction. The natural frequency of the siren of the car is 800 Hz and the surrounding temperature is 27^ C . The frequency heard by the truck driver as the car passes him

Options

  1. Aremains unchanged
  2. Bdecreases nearly by 232 Hz
  3. Cincreases nearly by 231 Hz
  4. Ddecreases nearly by 260 Hz

Correct answer

B. decreases nearly by 232 Hz

Step-by-step solution

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