Which of the following is an example of a longitudinal wave?

• A. Sound waves traveling through air
• B. Light waves traveling through a vacuum
• C. Waves on a stretched string
• D. Surface waves on the ocean

Answer: (A)

Verified step by step guidance

1. Understand the difference between longitudinal and transverse waves: In longitudinal waves, the particle displacement is parallel to the direction of wave propagation, while in transverse waves, the displacement is perpendicular to the direction of wave propagation.
2. Analyze sound waves traveling through air: Sound waves cause air particles to oscillate back and forth along the direction the wave travels, which matches the definition of a longitudinal wave.
3. Consider light waves traveling through a vacuum: Light waves are electromagnetic waves and are transverse, with electric and magnetic fields oscillating perpendicular to the direction of propagation.
4. Examine waves on a stretched string: These waves are transverse because the string moves up and down while the wave travels horizontally.
5. Look at surface waves on the ocean: These waves have both longitudinal and transverse components, but are generally considered surface waves, not purely longitudinal.