Sound waves are _____ waves.

Sound waves are _____ waves.

• A. longitudinal
• B. transverse
• C. surface
• D. circular

Answer: (A)

Sound waves are longitudinal waves. In a longitudinal wave, the particles of the medium move parallel to the direction the wave travels, creating compressions (high pressure) and rarefactions (low pressure) as energy moves through. For sound in air, the air molecules oscillate back and forth along the path the wave is moving, which is exactly what characterizes a compressional, or longitudinal, wave. Contrast this with transverse waves, where the particle motion is perpendicular to the direction of travel (like waves on a string or light). Surface waves occur at interfaces and involve motion that isn’t purely along the propagation direction, and circular waves describe ripples spreading outward from a point source in all directions, not the specific particle motion of sound.

Sound waves are longitudinal waves. In a longitudinal wave, the particles of the medium move parallel to the direction the wave travels, creating compressions (high pressure) and rarefactions (low pressure) as energy moves through. For sound in air, the air molecules oscillate back and forth along the path the wave is moving, which is exactly what characterizes a compressional, or longitudinal, wave.

Contrast this with transverse waves, where the particle motion is perpendicular to the direction of travel (like waves on a string or light). Surface waves occur at interfaces and involve motion that isn’t purely along the propagation direction, and circular waves describe ripples spreading outward from a point source in all directions, not the specific particle motion of sound.