ExamBro
ExamBro
AP EAMCET · PHYSICS · Waves and Sound

A train approaching a railway crossing at a speed of 120 kmph sounds a whistle of frequency 576 Hz, when it is 288 m away from the crossing. The frequency heard by the observer standing on the road perpendicular to the track from the crossing at a distance of 384 m is (Speed of sound in air =340 m s-1)

  1. A 632 Hz
  2. B 612 Hz
  3. C 512 Hz
  4. D 472 Hz
Verified Solution

Answer & Solution

Correct Answer

(B) 612 Hz

Step-by-step Solution

Detailed explanation

The figure below represents the observer, train and crossing. The speed of the observer, u=120 cosθ u=120×2883842+2882 u=120×35 km h-1 u=120×35×518 m s-1 u=20 m s-1 The formula for the frequency heard by observer, when…