The drawing shows four situations-A, B, C, and D-in which an observer and a source of electromagnetic waves can move along the same line. In each case the source emits a wave of the same frequency, and in each case only the source or the observer is moving. The arrow in each situation denotes the velocity vector, which has the same magnitude in each situation. When there is no arrow, the observer or the source is stationary. Rank the frequencies of the observed electromagnetic waves in descending order (largest first) according to magnitude.
(a) A and B (a tie), C and D (a tie)
(b) C and D (a tie), A and B (a tie)
(c) A and D (a tie), B and C (a tie)
(d) B and D (a tie), A and C (a tie)
(e) B and C (a tie), A and D (a tie)

Transcribed Image Text:

Observer Source o-