Deepen your understanding of sound waves, echo, and how sound reflects off surfaces.
Sound travels as a longitudinal wave, with compressions and rarefactions moving through a medium.
What are the two parts of a sound wave called?
Compressions (where particles are close together) and rarefactions (where particles are spread apart)
Why is sound called a longitudinal wave?
Because particles vibrate in the same direction as the wave travels
An echo is a reflected sound heard after the original sound, requiring the reflecting surface to be far enough away.
Why do you hear an echo in a large empty hall but not in a small room?
The reflecting surface needs to be far enough away for the reflected sound to arrive as a separate, distinguishable echo
What is the minimum distance typically needed for a human to perceive an echo?
About 17 metres, so the sound has time to travel to the surface and back before it would blend with the original sound
1. What is an echo?
2. Name the two parts of a sound wave.
3. Why is sound a longitudinal wave?
4. Why don't we hear an echo in small rooms?
5. What is needed for an echo to be heard?