A toy-car, blowing its horn, is moving with a steady speed of 5 m/s, away from a wall. An observer, towards whom the toy car is moving, is able to hear 5 beats per second. If the velocity of sound in air is 340 m/s, the frequency of the horn of the toy car is close to :
680 Hz
510 Hz
340 Hz
170 Hz
As we learnt in
Frequency of sound when observer is stationary and source is moving towards observer -
- wherein
speed of sound
speed of source
original frequency
apparent frequency
Correct option is 4.
Option 1)
680 Hz
This is an incorrect option.
Option 2)
510 Hz
This is an incorrect option.
Option 3)
340 Hz
This is an incorrect option.
Option 4)
170 Hz
This is the correct option.
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