In: Physics
A sound source A and a reflecting surface B move directly toward each other. Relative to the air, the speed of source A is 29.7 m/s, the speed of surface B is 63.5 m/s, and the speed of sound is 330 m/s. The source emits waves at frequency 1350 Hz as measured in the source frame. In the reflector frame, what are (a) the frequency and (b) the wavelength of the arriving sound waves? In the source frame, what are (c) the frequency and (d) the wavelength of the sound waves reflected back to the source?
Let the frequency of the sound from the reflector frame is no.
Given that the speed of the source A is vA=29.7 m/s.
The speed of the surface B is vB=63.5 m/s.
The frequency of the source sound ns=1350 Hz.
The speed of the sound vs=330 m/s.
a) For both the source and surface are moving, the frequency of the arriving sound
The frequency is 1768.98 Hz.
b) Let the wavelength of the arriving sound is .
The wavelength of the arriving sound is 0.187 m.
c) Let the frequency of the reflected sound from the surface B is nr.
The frequency of the reflected sound wave is 2387.627 Hz.
d) Let the wavelength of the sound reflected back to the source is .
The wavelength of the sound reflected back to the source is 0.138 m.