S3.9.6 For the adult
Sound as a wave
How does sound get from a drum to my ear, and why is space silent?
What this chapter teaches
Sound is a vibration passed from particle to particle as squashed and stretched parts that move outwards. The particles only shake to and fro. It needs a material, so it cannot cross empty space, though light can.
Three questions to ask
There is no one right wording. Listen for the idea.
- What do the particles of air do when a sound wave goes past?
- Why can an astronaut not hear a sound from outside the spaceship?
- How can a line of people show a sound wave?
After the chapter, the learner can
- Explain why sound cannot cross empty space
- Model a sound wave with a stretched spring or a row of people
What they copy into their notebook
Sound is a pattern of squashed and stretched parts that moves through particles. The particles only shake to and fro. It needs air, water or a solid, so space is silent.