A source is moving with constant speed `upsilon_(s) = 20 m//s` towards a stationary observer due east of the source. Wind is blowing at the speed of `20 m//s` at `60^(@)` north of east. The source has frequency `500 H_(Z)`. Speed of sound `= 300 m//s`. The frequency resgistered by the observer is approximately

Options

A. 541 Hz
B. 552Hz
C. 534Hz
D. 517Hz

Answer

C

Explanation

`f=f_(0)((C+V_(m)-V_(0))/(C+V_(m)-V_(S))),V_(m)=+V_(V)cos60^(@)=+10m//s`
`implies f=500[(300+10-0)/(300+10-20)]=500xx(310)/(290)~~534Hz" " to`