Final answer:
Considering an LTI system, a periodic and nonzero impulse response is indicative of instability. Waves can superpose regardless of their frequencies, and there are two types of interference: constructive and destructive. The amplitude of one wave can affect another when they interact, regardless of whether they are aligned or propagating along the same line.
Step-by-step explanation:
The statement regarding an LTI system is true if the impulse response (h(t)) is periodic and nonzero, it suggests that the system has an infinite impulse response that does not decay, which characterizes an unstable system in the context of Linear Time-Invariant (LTI) systems. In other words, for stability in LTI systems, the impulse response should ideally decay to zero as time approaches infinity. A periodic impulse response that doesn't decay indicates that the system could output signals of increasing amplitude over time, leading to instability.
Addressing statement 56 concerning wave superposition, it is true. Waves of different frequencies can indeed superimpose; this superposition is the principle behind interference patterns. Whether the frequencies are the same or different, when two waves meet, their amplitudes will add algebraically to form a resultant wave.
Statement 16 is also true. The two types of interference are indeed constructive and destructive interference. Constructive interference happens when the wave amplitudes align in the same phase and add together, increasing overall amplitude. Destructive interference occurs when the wave amplitudes are out of phase and subtract from each other, potentially leading to a reduced or zero resultant amplitude.
The statements regarding amplitude interaction in statements 58 and 9 are both false. The correct statements are that the amplitude of one wave is not affected by the amplitude of another wave unless they are interacting or overlapping in some way. This interaction is not dependent on their precise alignment (58) and can occur even if they are not propagating along the exact same line (9), as long as the waves intersect or overlap.