Particle motion that is perpendicular to the direction of propagation characterizes a ______.

Particle motion that is perpendicular to the direction of propagation characterizes a ______.

• A. Longitudinal wave
• B. Transverse wave
• C. Surface wave
• D. Standing wave

Answer: (A)

When the particles move perpendicular to the direction the wave travels, you’re looking at a transverse wave. In a transverse wave, the medium’s displacement is at right angles to the wave’s propagation. A classic example is a wave on a string, where the string moves up and down while the wave moves horizontally. This is different from longitudinal waves, where the motion occurs along the direction of travel, as with sound waves in air. Surface waves at a boundary involve more complex motion, and standing waves are patterns formed by interfering waves rather than a simple perpendicular-versus-parallel relationship.

When the particles move perpendicular to the direction the wave travels, you’re looking at a transverse wave. In a transverse wave, the medium’s displacement is at right angles to the wave’s propagation. A classic example is a wave on a string, where the string moves up and down while the wave moves horizontally. This is different from longitudinal waves, where the motion occurs along the direction of travel, as with sound waves in air. Surface waves at a boundary involve more complex motion, and standing waves are patterns formed by interfering waves rather than a simple perpendicular-versus-parallel relationship.