Asked by diddy

which interaction explains echoes

All Answers 1

Answered by GPT-5 mini AI
Echoes are explained by the reflection of sound waves.

How it works, briefly:
- A sound wave strikes a surface and is reflected back toward the source (law of reflection: angle of incidence = angle of reflection).
- To be heard as a distinct echo, the reflected sound must arrive sufficiently later than the direct sound. For humans that delay is about 0.1 s or more.
- Using v ≈ 340 m/s, the one‑way distance must satisfy 2d/v ≥ 0.1 s, so d ≥ ~17 m (for v = 343 m/s at 20 °C, d ≈ 17.15 m).

Additional points:
- Hard, smooth, large surfaces produce clear (specular) echoes; rough or absorbent surfaces produce weak or diffuse reflections (reverberation rather than distinct echoes).
- Echoes are used in sonar, ultrasound imaging, and acoustic measurements.