1. Does sound travel faster in water or air?
Moving Sounds
Developing: Illustrate a wave with labels
Secure: Explain how sound is reflected and absorbed.
Excelling: Create an instrument and explain how it works
Entrance Activity
Does sound travel faster in water or air?
Key words
amplitude
energy
frequency
medium
model
particles
pressure wave
sound wave
source
vacuum

2. We can use sound energy to break a glass!
Key Word Alert!
Sound Wave
Sound waves are created by the vibration of an object, which causes the air surrounding it to vibrate. The vibrating air then causes the human eardrum to vibrate, which the brain interprets as sound.
We can use sound energy to break a glass!

4. How did the sound break the glass?
Discussion Activity
How did the sound break the glass?
Extension
Draw a diagram showing how a sound wave travels

5. Teacher Explanation
Vibrating particles
Sound is produced when particles of air or another medium vibrate and compress together. They move horizontally and have energy. These particles have so much energy that they can cause a glass to smash by hitting it. Sound is a type of longitudinal wave
Slinky demo!

6. Longitudinal Waves
Assessment Activity
Complete the diagram of a longitudinal wave using the keywords.
Rarefaction
Wavelength
Compression

7. Does sound travel faster in water or air?
Moving Sounds
Developing: Illustrate a wave with labels
Secure: Explain how sound is reflected and absorbed.
Excelling: Create an instrument and explain how it works
Entrance Activity
Does sound travel faster in water or air?
Key words
amplitude
energy
frequency
medium
model
particles
pressure wave
sound wave
source
vacuum

8. Write down what you think happens when you hear an echo.
Discussion Activity
What is an echo?
Extension
Write down what you think happens when you hear an echo.

9. Teacher Explanation
Sound Control
A sound wave can be controlled in one of three different ways – it can be reflected, diffused or absorbed. Each of these reactions will depend entirely on the nature and composition of the material it comes into contact with, and each can be used to some extent in soundproofing.
Controlling sound!

10. Match the definitions and diagrams!
Assessment Activity
Match the definitions and diagrams!
Sound is bounced off a surface. This occurs on flat surfaces with a lot of mass like concrete or brick walls. Because the sound wave can't penetrate very far into the surface, the wave is turned back on itself. The sound bouncing back off the surface creates an echo.
When a sound wave hits an irregular surface like foam or carpet, the vibration breaks up and travels along many much smaller paths. This divides the energy of the wave, sending it in many different directions which reduces its energy faster.
When a sound wave hits a particular surface, the kinetic energy driving it is converted into a small amount of heat energy which dissipates, taking away power from the sound wave. This is sound insulation from things like foam and rubber.

11. Does sound travel faster in water or air?
Moving Sounds
Developing: Illustrate a wave with labels
Secure: Explain how sound is reflected and absorbed.
Excelling: Create an instrument and explain how it works
Entrance Activity
Does sound travel faster in water or air?
Key words
amplitude
energy
frequency
medium
model
particles
pressure wave
sound wave
source
vacuum

12. Discussion Activity
Making Instruments?

13. Explain your Kazoo
Assessment Activity
In your book write a paragraph explaining how a kazoo straw works and how it causes different sounds. Use keywords such as high, low, pitch, frequency, particles, medium and air!