Question

146. Two cars moving in opposite directions approacheach other with speed of 22 m/s and 16.5 m/srespectively. The driver of the first car blows a hornhaving a frequency 400 Hz. The frequency heard bythe driver of the second car is [velocity of sound340 m/s] :
(1) 350 Hz (2) 361 Hz
(3) 411 Hz (4) 448 Hz

Answer 1

Answer:

answer is 450 Hz I hope this helps you

Answer 2

The frequency of sound heard by the driver of the second car = 448.42 Hz

The car moving with velocity 22 m/s blows a horn having a frequency (f) of 400 Hz.

Using Doppler's effect equation -

frequency heard = f (velocity of sound w.r.t listener/velocity of sound w.r.t source)

Velocity of sound w.r.t listener = velocity of sound + velocity of second car

= 340 + 16.5 = 356.5 m/s

Velocity of sound w.r.t source = velocity of sound - velocity of first car

= 340 - 22 = 318 m/s

Frequency of sound heard = 400 ×(356.5/318)

= 448.42 Hz