A) 100 Hz
B) 103 Hz
C) 106 Hz
D) 97Hz
Correct Answer: B
Solution :
Given, as a source of sound S emitting waves of frequency 100 Hz and an observer O are located at some distance. Such that, source is moving with a speed of 19.4 m/s at angle \[60{}^\circ \] with source-observer line as shown in figure. The apparent frequency heard by observer \[{{f}_{0}}={{f}_{s}}\left[ \frac{v}{v-{{v}_{s}}\cos {{60}^{{}^\circ }}} \right]=100\left[ \frac{330}{330-19.4\times \frac{1}{2}} \right]\] \[=100\left[ \frac{330}{300-9.7} \right]=100\left[ \frac{330}{320.3} \right]\] \[=103.02Hz\]You need to login to perform this action.
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