How is an echo formed is it sound waves traveling into a soft surface sound waves bounce off of flat surface light waves pass through a shiny surface or light waves go around a smooth surface
An echo is formed when sound waves bounce off a surface and return to the listener. When a sound wave encounters a flat or hard surface, such as a wall or a cliff, it is reflected back towards its source due to the change in density between the medium the sound is traveling through (e.g. air) and the surface it hits. The reflected sound wave then reaches the listener's ears, creating the perception of an echo.
On the other hand, light waves do not directly contribute to the formation of echoes as they do not exhibit sound wave behaviors. Light waves tend to reflect, refract (bend), or pass through different types of surfaces based on their properties (shiny, smooth, etc.). Echoes, however, only refer to the reflection of sound waves.