A) \[2.0m{{s}^{-1}}\]
B) \[2.5m{{s}^{-1}}\]
C) \[3.0m{{s}^{-1}}\]
D) \[3.5m{{s}^{-1}}\]
Correct Answer: B
Solution :
Listener go from \[A\to B\] with velocity (u) let the apparent frequency of sound from source A by listener \[n=n\left( \frac{v-{{v}_{0}}}{v+{{v}_{s}}} \right)\] or \[n=680\left( \frac{340-u}{340+0} \right)\] The apparent frequency of sound from source B by listener \[n=n\left( \frac{v+{{v}_{0}}}{v-{{v}_{s}}} \right)=680\left( \frac{340+u}{340-0} \right)\] But listener hear 10 beats per second. Hence, \[n-n=10\] or \[680\left( \frac{340+u}{340} \right)-680\left( \frac{340-u}{340} \right)=10\] or \[2(340+u-340+u)=10\] or \[u=2.5m{{s}^{-1}}\]You need to login to perform this action.
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