Consider the following two situations in which a source emits sound with a frequency of 900 Hz. The velocity of sound (vs) in air is 340 m/s.
I. Source is moving at speed vs/3 toward an observer at rest.
II. Observer is moving at speed vs/3 toward the source that is stationary.
The frequencies of sound heard by the observers in the two situations are:
1
I ∶ 1350 Hz; II ∶ 1200 Hz
2
I ∶ 1200 Hz; II ∶ 1350 Hz
3
I ∶ 1200 Hz; II ∶ 1200 Hz
4
More than one of the above
5
None of the above