Physics for IGCSE & O level - Waves And Sounds (Section 5 - No. 19)
What is a 'rarefaction' in a sound wave?
A region where particles are close together
A region where particles are spread out
The highest point of a wave
The lowest point of a wave
הֶסבֵּר
In a longitudinal wave, a rarefaction is a region where particles are spread out.