Which statement best describes longitudinal waves?

• A. The particles of the medium oscillate parallel to the direction of wave propagation.
• B. Longitudinal waves cannot travel through solids.
• C. The particles of the medium oscillate perpendicular to the direction of wave propagation.
• D. The speed of a longitudinal wave is always less than the speed of a transverse wave in the same medium.

Answer: (A)

Verified step by step guidance

1. Understand the definition of a longitudinal wave: In a longitudinal wave, the particles of the medium oscillate parallel to the direction in which the wave travels.
2. Recall that in longitudinal waves, compressions and rarefactions occur as particles move back and forth along the wave's path.
3. Recognize that longitudinal waves can travel through solids, liquids, and gases because these media allow particles to compress and expand.
4. Contrast longitudinal waves with transverse waves, where particles oscillate perpendicular to the direction of wave propagation.
5. Note that the speed of longitudinal and transverse waves depends on the medium's properties, and one is not always slower or faster than the other in the same medium.