Chapter 2: Q22DQ (page 538)
In case 1, a source of sound approaches a stationary observer at speed u. In case 2, the observer moves toward the stationary source at the same speed u. If the source is always producing the same frequency sound, will the observer hear the same frequency in both cases, since the relative speed is the same each time? Why or why not?
Short Answer
The observer will not hear the same frequency in both circumstances because in the first case does not equal in the second.