Question

which wave has a disturbance that is parallel to the wave motion?
○ no wave has a disturbance that is parallel
○ surface
○ longitudinal
○ transverse

Explanation:

To determine the wave with a disturbance parallel to wave motion, recall wave types:

• Longitudinal waves: Particles oscillate parallel to the wave’s direction (e.g., sound waves).
• Transverse waves: Disturbance is perpendicular (e.g., light, water ripples).
• Surface waves: Combine transverse and longitudinal, not purely parallel.
• The first option is incorrect (longitudinal waves exist with parallel disturbance).

Thus, longitudinal waves have disturbances parallel to wave motion.

Answer:

longitudinal (the option labeled "longitudinal")