In order to determine the doppler shift in perceived sound frequency, the following variables must be known:
I. speed of sound in medium
II. time of interaction between sound source and detector
III. distance between source and detector
IV. frequency of emitted sound
a) I only
b) I and III
c) II and IV
d) I and IV
Explanation
The equation for calculating the doppler effect on perceived frequency relies on the actual frequency of emitted sound, speed of sound in the transmitting medium, and the relative velocities of the source and detector:
a) I only, incorrect. Choice IV is also required.
b) I and III, incorrect. Distance is not a variable in the doppler equation.
c) II and IV, incorrect. Time of interaction is not a variable in the doppler equation.
d) I and IV, correct. Furthermore, the relative velocities of the detector and source are required.
