What is wavelength?

What is wavelength?

• A. The distance from one point of a sound wave to the same point on the next wave
• B. The speed of sound in the medium
• C. The rate at which sound energy is transferred
• D. The frequency of the wave

Answer: (A)

Wavelength is the spatial distance between identical points on successive cycles of a wave—such as from one crest to the next crest or from one compression to the next compression in a sound wave. It describes how stretched out the wave is in space. For a wave moving through a medium, wavelength relates to speed and frequency by the equation λ = v / f, so faster waves or lower frequency give longer wavelengths, while higher frequency or slower speed gives shorter ones. For example, in air at room temperature the speed of sound is about 343 meters per second; a 343 Hz tone has a wavelength of roughly 1 meter. The other descriptions don’t fit because the speed of sound is how fast the wave pattern travels, not the spacing between cycles; the rate of energy transfer refers to intensity or power per area, not wavelength; and frequency is how many cycles occur per second, not how far apart the cycles are in space.

Wavelength is the spatial distance between identical points on successive cycles of a wave—such as from one crest to the next crest or from one compression to the next compression in a sound wave. It describes how stretched out the wave is in space. For a wave moving through a medium, wavelength relates to speed and frequency by the equation λ = v / f, so faster waves or lower frequency give longer wavelengths, while higher frequency or slower speed gives shorter ones. For example, in air at room temperature the speed of sound is about 343 meters per second; a 343 Hz tone has a wavelength of roughly 1 meter.

The other descriptions don’t fit because the speed of sound is how fast the wave pattern travels, not the spacing between cycles; the rate of energy transfer refers to intensity or power per area, not wavelength; and frequency is how many cycles occur per second, not how far apart the cycles are in space.