1. How do we know sound energy exists?
Starter 10/3
How do we know sound energy exists?

2. Sound

3. Sound Waves Sound waves in the air travel COMPRESSIONALLY.
This means that sound waves don’t travel too well through the air.

4. Sound Waves BUT, sound waves can travel through a solid TRANSVERSLY.
This means sound wave can travel much farther through solid materials.

5. Sound Waves
Train robbers use to put their ears to the metal rails of the train to send messages to each other.

6. Sound Waves
The speed of sound = meters / second (That’s about 768 miles/hr)
The speed of light = 299,792,458 meters/second
WHY do you see something first, THEN hear it later? (like fireworks)

7. Characteristics of sound waves:
Amplitude = Volume
Wavelength/Frequency = Pitch

8. Sound Waves Let’s practice changing these characteristics: Amplitude
high
short
Amplitude
Wavelength
low
long

9. Sound Waves
Can you make an accurate wave for a certain type of music?

10. Sound waves
Long objects (pipes, keys, whistles) generate LONG wavelengths
Short objects generate SHORT wavelengths
Demo time 

11. Sound Waves

12. Sound waves
Ears can have issues…

13. Sound waves
Ears can have issues…

14. Sound waves
Sometimes ears need to be replaced: