1. Agenda: Waves and Sound quiz next Wednesday
Do this:Take out your Homework.
Title page “Sound Notes Day 2”

2. Standard: Explore the wave nature of sound and electromagnetic radiation. What am I learning today? How do sound waves travel?

3. What will I do to show that I learned it
What will I do to show that I learned it? I will write a summary of my notes on the Doppler Effect and Wave Interactions

4. Sound Travel
Extension

5. How does sound travel through different states of matter?

6. Sound travels through all forms of matter.

7. Speed of Sound
The speed of sound depends on the medium it travels through.

8. What Forms of Matter can Sound Travel Through?
Gas: sound travels easily through gases
It travels about 1,129 feet per second through air. (That’s how fast it travels when you talk!)
Liquids: Sound travels through water about 4,794 feet per second. (Think of what ripples look like in the water and how they spread.)
Solids: Sound travels through a solid like wood at a rate of 12,620 feet per second. Sound travels fastest through solids!
Sound cannot travel through a vacuum (a space that is “empty” of matter).

9. Breaking the Sound Barrier
“Sonic Boom”

10. Why does sound travel fastest in a solid?

11. Solid- molecules are packed tightly Examples: rock, metal, wood Solid =

12. Liquid- molecules are close together Example: water Liquid =

13. Gas- molecules spread apart Example: air Gas =

14. Sound travels fastest through solids because the molecules are tightly packed together

15. Sound travels fastest through solids

16. Vacuum: a place where there are NO molecules (outer space)
*There is no sound in outer space because there are no molecules (there is NO matter)

17. What do you think?
A tiny piece of space junk hits this space shuttle. There are two astronauts in the picture – one inside the capsule, and one outside. Can either of them hear the impact?

19. Bell in a Bell Jar

20. The Doppler WHAT?

21. The Doppler Effect

22. The Doppler Effect Doppler Effect:
The change in pitch (frequency) as a sound gets closer to you.

23. The Doppler Effect *The ______a sound gets, closer
the _______the pitch.
*The __________ a sound gets,
closer
higher
further away
lower

24. The Doppler Effect
Draw this now!...

25. The Doppler Effect “Big Bang Theory – Doppler Effect”

26. What are the interactions sound waves undergo?

27. Reflect/Absorb

28. *reflection: the bouncing of sound off of a surface

29. *absorption: the disappearance of a sound wave into a surface

30. *The harder the surface, the more sound is reflected.

31. *The softer the surface, the more sound is absorbed.

32. Echo…Echo…Echo…Echo

33. echo: a reflected sound wave

34. Echo = Communication

35. sonar and echolocation are both the finding of an object using reflected sound

36. *echolocation= dolphins, bats
So…What’s the difference between sonar and echolocation?
*sonar = ships, submarines
Warships using sonar to find submarines. It’s thought the war ships sonar disrupts dolphins ultrasound system.
*echolocation= dolphins, bats

38. Resonance
A phenomenon that occurs when two objects naturally vibrate at the same frequency.
The sound produced by one object causes the other object to vibrate.
Musical instruments use resonance to generate sounds. An acoustic guitar has a hollow body that amplifies the sounds.

39. Summarize your notes
The Doppler Effect
Wave Interactions

40. Interference
Constructive interference-when a compression from one wave overlaps the compression of another wave.
Destructive interference-the compression of one wave overlaps the rarefaction of another wave.

41. Sound Waves Videos: Echoes
“The Boy Who Could See Like a Bat” (3:53)
Real Life Bat Man (2:54)
“Quack Science” video on discovery education (21 min)