Final answer:
The statement about AIS transmission frequencies is true. It's also true that waves can superimpose with different frequencies, and the Doppler effect can occur with all kinds of waves, not only sound. Option B is correct.
Step-by-step explanation:
The statement that dynamic information is transmitted every 2 to 10 seconds depending on vessel's course and speed, and every 6 minutes when anchored is related to the Automatic Identification System (AIS) used in maritime navigation.
It is true that AIS transmits dynamic information at different intervals based on the vessel's status and movements. This system plays a vital role in ensuring maritime safety by providing real-time data to other nearby ships and maritime authorities.
Waves can superimpose regardless of whether they have the same or different frequencies. This phenomenon is known as superposition, and it is a fundamental principle of wave interference. Therefore, the statement that waves can superimpose if their frequencies are different is true.
As for the Doppler effect, it is a change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. It does not occur only when the sound source is moving; it can also occur if the observer is moving while the source remains stationary.
Hence, the statement that the Doppler effect occurs only when the sound source is moving is false. The Doppler effect can also occur with waves other than sound waves, such as electromagnetic waves like light. So, it is true that the Doppler effect also occurs with other types of waves.
The observed frequency does not become infinite when the source moves at the speed of sound; instead, a large amplitude pressure wave is produced, which is heard as a sonic boom. Therefore, the statement that the observed frequency becomes infinite at the speed of sound is false.