Brainlag PlusHow sound travels through solids, liquids and gases, how the ear works and why hearing has limits, and distances from echoes.
Vibrating particles
A sound wave is a longitudinal wave: particles vibrate back and forth along the direction the wave travels, passing the vibration on.
With no particles, as in space, there is no sound.
Sound is fastest in solids, slower in liquids and slowest in gases (about 330 m/s in air, 1500 m/s in water, around 5000 m/s in steel).
When sound passes into a new material its frequency stays the same (the source sets it). The speed changes, so by v = f λ the wavelength changes too.
The rest of this lesson and its 9 practice questions are in Plus.
Screen 1 of 4, free to read.
- 9 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards