Lesson Plan 5: The speed and nature of sound
The speed and nature of sound (Page 25 of the Teacher's Pack)
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Suitable for: 11-14 years
Curriculum and learning links:
- Calculate the speed of sound and compare it with the speed of light.
- Explain why sound cannot travel through a vacuum.
- Explain why sound travels fastest in solids and slowest in gases.
Clip 13: Speed of sound - Jem and Dallas demonstrate the speed of sound by shouting down 340 metres of tubing. The sound emerges from the other end after a one second delay.
Clip 14: Silence! - Jem places an angle grinder in an evacuated bell jar to demonstrate that sound cannot travel through a vacuum.
Clip 15: Stirring sounds - Dr Yan demonstrates why the sound of the spoon hitting the mug changes when you stir a hot drink.
Clip 16: Bubble and squeak - Dr Yan investigates balloons filled with gases of different densities (He and SF6). He shows how helium makes your voice squeakier but not higher and that it is the harmonics that change rather than the pitch.