Which statement about sound propagation in a vacuum is true?

Which statement about sound propagation in a vacuum is true?

• A. Transverse Waves
• B. Propagation Speed Increases To 3,300,000 M/s
• C. Cannot Travel
• D. Speed Of Light

Answer: (B)

Sound needs a medium to propagate because it travels as pressure variations carried by particles that compress and rarefy as the wave passes. In a vacuum, there are no particles to carry those vibrations, so there is nothing to transmit the sound. That means sound cannot travel in a vacuum. The idea that sound would be a transverse wave doesn’t fit, since even in a medium like air, sound is a longitudinal wave—compressions and rarefactions move along the direction of the wave. Without a medium at all, there’s no propagation to even classify as transverse or longitudinal. The notion of a fixed propagation speed in a vacuum isn’t applicable because there’s no medium to support any sound wave. And the speed of light is unrelated to sound; it’s a different phenomenon entirely.

Sound needs a medium to propagate because it travels as pressure variations carried by particles that compress and rarefy as the wave passes. In a vacuum, there are no particles to carry those vibrations, so there is nothing to transmit the sound. That means sound cannot travel in a vacuum.

The idea that sound would be a transverse wave doesn’t fit, since even in a medium like air, sound is a longitudinal wave—compressions and rarefactions move along the direction of the wave. Without a medium at all, there’s no propagation to even classify as transverse or longitudinal. The notion of a fixed propagation speed in a vacuum isn’t applicable because there’s no medium to support any sound wave. And the speed of light is unrelated to sound; it’s a different phenomenon entirely.