how many complete wavelengths are present in the sound wave shown?\n1\n2\n4\n6

Explanation:

Step1: Recall wavelength definition

A wavelength is the distance between two consecutive points in phase (e.g., two crests or two troughs).

Step2: Count wavelengths in the wave

By visually inspecting the sound - wave shown, we can count the number of complete cycles. Each complete up - and - down pattern represents one wavelength. Counting these patterns, we find there are 6 complete wavelengths.

Answer:

6