1. OK everyone get ready to learn a new vocabulary term.

2. Pitch
Today we are going to learn about pitch.

3. Doppler Effect
The Doppler effect,

4. Interference
interference,

5. Resonance
And resonance.

6. Before we define these terms, let’s review some other words that you already learned, and make sure you are firm in your understanding.

7. sound waves
Sound waves are longitudinal waves that travel through a medium.

8. medium
A medium is any material that waves can travel through.

9. vibration
Vibration is the movement of particles that occurs in solids, liquids, or gases.

10. compression
Compression is the area in a longitudinal wave where particles are closest together.

11. rarefaction
Rarefaction is the area in a longitudinal wave where the particles are furthest apart.

12. frequency
Frequency is the number of wavelengths that pass a set point, per second.

13. Now let’s pause for a moment to review the information we have covered already.

14. What is a sound wave?

15. What sections are seen in a sound wave?
Rarefaction and compression

16. What is frequency?
Frequency is the number of wavelengths that pass a set point, per second.

17. Pitch
First we are going to look at pitch.

18. pitch
Let’s define what pitch is.

19. pitch: the perception of how high or low a sound seems.
A sound’s pitch is how low or high it seems to be when you hear it.

20. High Frequency = High Pitch
The higher the frequency, the higher the pitch.

21. Doppler Effect
Now let’s define what the Doppler Effect is.

22. Doppler Effect: the change of pitch you hear when a sound source is moving closer and further away from you
The Doppler effect is the change of pitch you hear when a sound source is moving closer and further away from you.

23. If you are standing near the train, the whistle sounds high.

24. But after the train passes you, the whistle’s pitch drops and it sounds low.

25. Doppler Effect
The pitch of the whistle is dependent on the train’s location relative to you.

26. Now let’s pause for a moment to review the information we have covered already.

27. What is pitch?
A sound’s pitch is how low or high it seems to be when you hear it.

28. What change is the a scientist observing
as a result of the Doppler Effect?
The Doppler effect is the change of pitch you hear when a sound source is moving closer and further away from you.

29. True or False: The Doppler Effect is created because the initial
vibration changed.
False.

30. interference
Next, let’s define interference.

31. interference: occurs when waves overlap, combine, and form a new wave

32. Interference Constructive Destructive
There are two types of intereference.

33. Constructive Interference
Constructive Interference occurs when 2 compressions from 2 different sound waves meet and combine to form a new wave with higher intensity and a larger amplitude.

34. Destructive Interference
Destructive interference occurs when a compression and a rarefaction from difference waves combine to create a less intense and smaller amplitude wave.

35. This is how noise canceling headphone work
This is how noise canceling headphone work. They create destructive interference by creating a wave that is exactly opposite of the sound from the environment.

36. resonance
Next, let’s define resonance.

37. resonance: occurs when an object absorbs sound energy from another object vibrating at the same frequency
Resonance occurs when an object absorbs sound energy from another object vibrating at the same frequency.

38. resonance = larger amplitude+
6 KHz
6 KHz
When resonance occurs, the amplitude of the new wave is larger than the amplitude of the separate objects’ wavelengths.
resonance = larger amplitude

39. Now we are going to look at an example of resonance.

40. Guitar
When the guitar string vibrates,

41. Guitar
The air inside the guitar vibrates by resonance.

42. Increasing amplitude
Amplifying the sound of the string.

43. Now let’s review all the information we have covered today.

44. What is resonance?

45. Which is affected by the location of
a sound’s source?
Doppler Effect
Vibration
Resonance
Medium

46. Which is affected by the location of
a sound’s source?
Doppler Effect
Vibration
Resonance
Medium

47. Which type of interference creates waves with large amplitudes?
Deletion
Destructive
Constructive
Completion
The distance between to like points.

48. Which type of interference creates waves with large amplitudes?
Deletion
Destructive
Constructive
Completion
The distance between to like points.

49. Which type of interference creates waves with decreased intensity?
Deletion
Destructive
Constructive
Completion
The distance between to like points.

50. Which type of interference creates waves with decreased intensity?
Deletion
Destructive
Constructive
Completion
The distance between to like points.

51. What occurs when waves overlap
and create new waves?
interference

52. Remember!!!
So remember!
<keep this slide>

53. pitch: the perception of how high or low a sound seems.
A sound’s pitch is how low or high it seems to be when you hear it.

54. Doppler Effect: the change of pitch you hear when a sound source is moving closer and further away from you
The Doppler effect is the change of pitch you hear when a sound source is moving closer and further away from you.

55. interference: occurs when waves overlap, combine, and form a new wave

56. resonance: occurs when an object absorbs sound energy from another object vibrating at the same frequency
Resonance occurs when an object absorbs sound energy from another object vibrating at the same frequency.

57. Thanks for watching, and please continue watching CAPs available from this website.

58. Questions or Comments to Michael Kennedy, Ph.D.
This Video Created With Resources From:
Cooperative Agreement # R324B130023
Curry School Foundation’s Research and Development Fund
Questions or Comments to Michael Kennedy, Ph.D.

59. Activity
Objective: Students will understand the relationship between frequency and pitch. Activity: Student will work through 2 lab stations. The first will allow them to look at how the length of a ruler affects the pitch and frequency the sound makes. The second will allow the student to make “kazoos” and see how they can change the pitch.
Materials:
Ruler
Plastic straw
Scissors
worksheet
Resources: