A) 550 Hz
B) 555.5 Hz
C) 720 Hz
D) 500 Hz
Correct Answer: C
Solution :
Key Idea Apply Doppler's effect. Whenever there is a relative motion between a source of sound and the observer (listener), the frequency of sound heard by the observer is different from the actual frequency of sound emitted by source. Case I Case II [for case I] \[{{V}_{C}}\ne {{V}_{B}}\ne {{V}_{A}}\] ...(i) [for case II] \[{{V}_{C}}={{V}_{B}}={{V}_{A}}\] ... (ii) From Eqs. (i) and (ii), we get \[\text{m}{{\text{s}}^{-1}}\]\[\text{20m}{{\text{s}}^{-1}}\]HzYou need to login to perform this action.
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