Superposed vibrations produce a net displacement that is the sum of the individual sinusoids

Evidence

That is, the position of the smaller tines is first displaced by the lower frequency mode and then figured from there by adding the displacement of the smaller fork’s higher frequency mode, making y(t) a sum of two sinusoids of different frequencies (see figure 3.11). — Eric J. Heller, Why You Hear What You Hear- An…, 308

Categorization

• DEFINE: Introduces the superposition principle for vibrating modes — net motion as a sum of component sinusoids.