Final answer:
It is false that binary sequences cannot be used to represent sound, as binary numbers can represent digital audio. The frequency of sound does not become infinite at the speed of sound, which makes that statement false. The superposition of waves with different frequencies is true and fundamental to wave interference.
Step-by-step explanation:
The statement that 'Binary sequence cannot be used to represent sound' is false. Binary sequences can indeed be used to represent sound in the form of digital audio. This is done through a process called analog-to-digital conversion where sound waves are sampled at discrete intervals and then represented as binary numbers.
The question about the observed frequency becoming infinite when the source is moving at the speed of sound is also false. While the frequency will increase as the source approaches the speed of sound, it does not become infinite. It potentially reaches a maximum at the speed of sound and may become inaudible or distorted beyond that point.
Regarding the superposition of waves, it is true that waves can superimpose if their frequencies are different. This principle is a fundamental concept in the study of wave interference and results in various phenomena such as beats and constructive or destructive interference.