Solve this :

A source starts from rest at t = 0 and moves away from a stationary observer with a constant acceleration  5   m s - 2 . At t = 0 source is 160 m away from observer. If it emits sound of frequency 700 Hz the frequency heard by observer at t= 2.5s is  _____

[velocity of sound = 340 m s - 1 ]

1) 600 Hz              2) 640 Hz
3) 680 Hz              4) 690 Hz​
 

Dear Student ,
When the source moves away from the observer then ,
Velocity of the source at t=2.5 s is ,vo=uo+at=0+5×2.5=12.5 m/schange in frequency,f'=fv-vsv=700×340-12.5340=674.26 m/sSo here the correct option is 3.Regards

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