Varying which of the following wave characteristics will cause the length of sound waves to vary?

The length of sound waves is directly affected by the wavelength, which is the distance between successive crests or troughs of a wave. Wavelength is inversely related to frequency; as the frequency of a sound wave increases, the wavelength decreases, and vice versa. This relationship means that when you alter the frequency of the sound wave, you will also alter its wavelength, thereby changing the length of the wave.

Increasing the frequency results in more cycles per second, which shortens the distance between crests, thus reducing the wavelength. Conversely, lowering the frequency increases the wavelength. Understanding this relationship is essential in fields like acoustics and audio engineering, where the manipulation of sound characteristics is crucial.

Amplitude, on the other hand, relates to the loudness or intensity of the sound and does not affect the length of the wave. Pressure is associated with sound intensity and propagation but does not determine the wave's length. Therefore, wavelength is the characteristic that directly influences the physical length of sound waves.