Echoes from Sound Reflection

Steps:

• Identify that an echo is a repeated sound heard after the original.
• Recall sound travels as waves that interact with surfaces.
• Determine the interaction where waves bounce back to the source.
• Match this to the process causing the delayed return of sound.

Why C is correct:

• Reflection is the bouncing of sound waves off a surface, like a cliff, sending them back to the listener as an echo, per the law of reflection (angle of incidence equals angle of reflection).

Why the others are wrong:

• A. Absorption: Sound energy is taken in by the surface, reducing or eliminating echoes.
• B. Dispersion: Sound waves spread out in different directions, not causing a distinct repeated sound.
• D. Refraction: Sound waves bend when passing through varying media, altering path but not producing echoes.

Final answer: C