1. Sound Waves
WALT: describe and identify the difference between frequency and amplitude
I must be able to state how we hear sound
I should identify how changes in loudness and pitch occur and can identify these on a wave diagram

2. You have 8 boiling tubes
Fill each of them with different amounts of water and blow on them to produce a musical instrument.
See if you can make a song. You have 5 minutes.

3. The loudness and pitch of the sound depend on the size and frequency of the sound waves
Turn to p.429 and p.430 – let’s read it together

4. Amplitude = loudness

5. Frequency - pitch

7. So how was the level of water in the boiling tubes affecting the wavelength/amplitude of sound vibrations when you were blowing?

8. Can light and sound both travel through a vacuum?
Let’s read p. 425 and 426
Next….design an experiment to find out who has the most sensitive hearing in the group
1. What are your input and outcome variables?
2. How will you keep it a fair test?

9. Echoes Sound waves bounce off an object (e.g. a wall)
Let’s read through p.424
Now spend 2 minutes discussing how you could measure the speed of sound from an echo (clue: you can calculate your distance from a wall)
Let’s read through the answer on p.427

10. Questions
Now answer some questions: Lewis and Foxcroft Physics books – p.269 Q4 and 5.

11. Plenary
How might changes in frequency and amplitude of a sound affect the way we hear?