In: Physics
You are riding your bicycle directly away from a stationary source of sound and hear a frequency that is 0.7% lower than the emitted frequency. The speed of sound is 346 m/s. What is your speed?
Let the frequency of the source be F.
Given that frequency heard is 0.7 % lower than the initial
frequecy
F ' =
( 100% - 0.7 % ) F
F ' =
99.3 % F
or F ' = 0. 993 F
F ' / F = 0. 993
According to Doppler effect, the frequency of the sound heard is
given as
F ' = F [ V / ( V+ Vs) ]
Here V is speed of sound and Vs is speed of the
observer
F' / F = [ V / ( V+ Vs)
]
Plug in values
0.993 = [ 346 / ( 346 + Vs ) ]
Solving for Vs
Vs = 348.44m/s - 344 m/s
= 4.44 m/s ANSWER
I hope help you.....