Final answer:
The cross-over frequency, analogous to the beat frequency between two sound waves such as musical notes D and C with given frequencies of 297 and 352 Hz, is calculated as 55 Hz, which is the absolute difference between the two frequencies.
Step-by-step explanation:
The subject of the question is related to the concept of beat frequencies in Physics, specifically within the context of waves and sound. The question asks about finding the crossover frequency, which is similar in concept to finding the beat frequency between two sound waves.
The beat frequency is defined as the absolute value of the difference between the frequencies of two waves (fB = |f1-f2|). For instance, if we have two sound waves with frequencies f1 and f2, the beat frequency fB is the frequency at which the amplitude of the combined sound waves fluctuates. This is experienced as an audible pulsation or warble in the sound.
Given the provided frequencies for the musical notes D and C (297 and 352 Hz), to find the beat frequency, we would subtract one from the other: |297 Hz - 352 Hz| = 55 Hz. Thus, the beat frequency between D and C is 55 Hz.