sound y 5

1. Sound

2. How do we hear sound?
3 steps occur to hear sound

3. How do we hear sound?
First
The object that sound comes from
vibrate.

4. Example 1

5. Example 1
The vocal cords vibrate so sound is
produced.

6. Example 2
Tuning fork

7. Example 3
Speakers

8. Watch video of instruments vibrating

9. Conclusion
Sound results from vibration

10. How do we hear sound?
second
The vibration is transferred to the
air.

11. The air contains atoms or
particles, these particles hit
each other.

12. Watch video of air particles

14. Compression
Regions of air that have
many particles

15. Rarefaction
Regions of air that have few
particles

16. The continuous compression and
rarefaction of air particles is called
Sound wave

17. Drums produce sound when they are
hit

18. Stringed instrument produce sound
when they are
plucked

19. Wood wind instrument produce sound
when they are
blown

25. Sound travels through air particles ( gas )
Does the sound travels through solid
particles ?
Does the sound travels through liquid
particles ?
Video 3

26. Which medium the sound travels the
fastest?
Why ?
Because the particles are very
close to each other
Solid

27. Which medium the sound travels the
slowest?
Why ?
Because the particles are far from
each other.
Gas

28. How do we hear sound?
third
The vibrations reaches our ear and
is translated to sound in our brain

29. Outer ear
Middle ear
Inner ear
Ear drum Cochlea

30. •When the sound waves reaches our ear
drum, it hits it and our ear drum starts to
vibrate.
•Next the three bones attached to the ear
drum starts to vibrate.
•The cochlea then translates these vibrations
into signals that is sent to the brain by our
nerves.
•The brain translates these signals into
sound.

31. Properties of sound

32. Pitch
It can be high or low
Sharp Thick
High pitch
Is produced by :
- Short objects
- Tight ( stretched )objects
Low pitch
Is produced by :
- Long objects
- Looseobjects

33. Volume
It can be loud or soft (quiet)

34. We measure the sound volume
using an instrument called
Sound level meter
Unit is decibel ( dB )

35. Frequency
The number of times an object vibrates per
second.
Unit:
Hertz (Hz).

36. Low pitch
sounds has
lower
frequency.
High pitch
sounds has
higher
frequency.

37. How to change pitch?
High pitch
Short guitar string
Vibrates fast
causing high pitch

38. Low pitch
Long guitar string
Vibrates slowly
causing low pitch

39. Why in picture 2 you hear the sound
back ?
When the sound waves energy
hits a hard surface the energy
bounces back.

40. Why in picture 1 you don’t hear the
sound back ?
When the sound waves energy
hits a soft surface the energy is
absorbed.

41. Does that mean the sound energy is
not absorbed when it hits a hard
surface ?
No, it is absorbed but not as it
hits a soft surface

42. So the sound that bounces back is
called
Echo

43. Hard or Soft
Hard

44. Hard or Soft
Hard

45. Hard or Soft
Soft

46. Hard or Soft
Soft

47. Hard or Soft
Hard

48. Hard or Soft
Soft

49. Hard or Soft
Hard

50. Hard or Soft
Hard

51. Hard or Soft
Soft

52. Hard or Soft
Hard

53. Hard or Soft
Soft

54. Hard or Soft
Hard

55. Hard or Soft
Hard

56. Hard or Soft
Soft

57. Hard or Soft
Soft

58. Hard or Soft
Hard

59. Hard or Soft
Soft

60. Hard or Soft
Soft

61. Types of waves
Longitudinal
waves
Transverse
waves
Example : sound
energy
Example : light
energy