Echoes from Sound Reflection

Steps:

• Sound waves travel from the source to the cliff face.
• Upon reaching the cliff, the waves bounce back toward the person.
• The bounced waves reach the ear after a short delay, creating the echo.
• This identifies the process as reflection, not other wave behaviors.

Why C is correct:

• Reflection occurs when sound waves rebound off a surface, as defined in wave physics, directly causing the echo to return to the source.

Why the others are wrong:

• A. Absorption: Sound energy is taken in by the surface, reducing intensity without bouncing back.
• B. Dispersion: Waves spread out in different directions, not producing a distinct returning echo.
• D. Refraction: Sound waves bend due to medium changes, altering path but not reversing direction.

Final answer: C