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A bat flies at a steady speed of 4 m s^(-1) emitting 90 kHz sound waves and is flying towards a wall. It detects a reflected signal at a frequency (Take speed of sound = 340 m s^(-1) ) |
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Answer» 90.1 KHZ velocity of sound, v = 340 m `s^(-1)` Frequency emitted by the bat, `upsilon` = 90 kHz As source (bat) is moving towards the wall, the apparent frequency of sound striking the wall is `upsilon.=upsilon[v/(v-v_s)]`....(i) On REFLECTION , wall ACTS as source and bat is the observer `therefore upsilon..=upsilon.[(v+v_o)/v]=upsilon[(v+v_o)/(v-v_s)]` [USING (i)] `=90[(340+4)/(340-4)]=(90xx344)/336`=92.1 kHz |
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