A person going away from a factory on his scooter at a speed of 36 km/h listens to the siren of the factory.…
A person going away from a factory on his scooter at a speed of 36 km/h listens to the siren of the factory. If the main frequency of the siren is 600 Hz and a wind is blowing along the direction of the scooter at 36 km/h, find the main frequency as heard by the person. Velocity of sound in air = 340 m/s)
Solution
Sol. The given situation is shown below
---> v$_{s}$ = 0 ---> v$_{o}$ = 36 km/h
. S . O = 10 m/s
---> v
---> w
Wind speed, w = 36 km/h = 10 m/s
$f' = f \left(\frac{v + w - v_o}{v + w - v_s}\right) = 600 \left(\frac{340 + 10 - 10}{340 + 10 - 0}\right)$
$= 582.86$ Hz
Answer: $582.86$ Hz