1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# A train running at 108 km h−1 towards east whistles at a dominant frequency of 600 Hz. Speed of sound in air is 340 m/s. What frequency will a passenger sitting near the open window hear ? (b) What frequency will a person standing near the track hear whom the train has just passed ? (c) A wind starts blowing towards east at a speed of 36 km h−1. Calculate the frequencies heard by the passenger in the train and by the person standing near the track.

Open in App
Solution

## (a)Velocity of passenger with respect to the train is zero. So, Required frequecny =500 Hz (b)Frequency heard by the person standing near the track, n=v+v0v+vs×n0 =340+0340+30×500=459Hz (c)When the wind starts blowing towards east. Frequency heard by passenger is unaffected. But frequency heard by passenger is unaffected. But frequency heard by person stadly near the track, n=(v−vair)(v−vair)+vs×n0 =(340−10)(340−10)+30×500 =458 Hz

Suggest Corrections
2
Join BYJU'S Learning Program
Related Videos
Doppler's Effect
PHYSICS
Watch in App
Join BYJU'S Learning Program