This document discusses how sound travels and is produced. It explains that sound needs a medium like air or water to travel through, and that the medium vibrates but does not move with the sound. It also summarizes that larger vibrations produce louder sounds, larger objects make lower frequency sounds, and factors like length, thickness, and tension determine the frequency of sounds from strings.

1. SOUNDS GOOD!
From musical boxes
to iPods

2. Space
Walk
Aug 2005
Stephen
Robinson
outside
Discovery
NASA picture
2

3. Can he call to those inside the
space ship as he works?
3
NASA picture

4. Connected to the space ship by
a line
4
Why?
NASA picture

5. 5
Let’s play
some
games !

6. Sound moves this way
6
Sound dance
steps
 The bunches move along the line.
 The children do not move along!

7. Sound travels to your ear
7
Sound
The air vibrates
but does not travel from
the alarm to the ear.

8. Large ears to collect sound
 Our ears are
on the side
of our
heads.
 We can play
a game to
find out why.
8

9. ?
Why
does
Mittens
look
unhappy?
9

10. Whales sing
to each
other.
10
Sound
travels
through
water.

11. 11

12. 12
Bush telephone
game
 Sound travels through the string

13. 13
Telephones --
 Are like a sound system
The electrical
signal is
amplified
A microphone
changes sound to an
electrical signal.
A loudspeaker
changes the electrical
signal to sound.

14. Telephones --
 The message travels through miles
of wires as an electrical signal.
14
microphone
loudspeaker
electrical signal

15. Mobile phones use radio
Sound - electrical signal - radio signal - electrical signal - sound
In one phone the
In the second phone
sound is changed
the radio signal is
into an electrical
changed into an
signal then into a
electrical signal then
radio signal.
Mobile into sound.
phone
beacons
15
Radio signal
Sound - electrical signal - radio signal - electrical signal - sound

16. 16
What is this?
What
sound
does she
make?

17. 17
What are these?
 What
sound do
they
make?

18. What sound does this make?
 How does it
make the
sound?
18

19. Bells
 What
sounds will
they make?
19

20.  blow
20
Straw oboes
 Listen as the straw is snipped.

21. 21
Size matters!
Large things make
___________ sounds
Small things make
___________ sounds

22. 22
New words:
 High pitch =
high frequency
 Low pitch =
low frequency

23. 23
Size matters!

24. What else changes sounds?
How do you
tune a violin?
Let us try to
make a string
instrument.
24

25. What have we learned?
 Vibrating objects make sounds
 Sound needs a medium through which to travel
25
– air, water, string - - -
 The medium vibrates but does not travel with the
sound
 Large vibrations make loud sounds
- small vibrations make quiet sounds
 Large objects make low frequency sounds
- small objects make high frequency sounds
 In strings the frequency of the sound depends
on the length, thickness, and tension.

26. Can you spot the baby?
26
Sound
has
lots
of
uses

27. Ultrasound is very, very high
frequency sound.
It is used to see inside people
- to see
babies before
27
they are born
if a heart is
working well
blood flow

28. Knowledge about sound helps -
 Musical instrument design
28
and playing them
 Sailors find how deep the water is
 Building design
so we hear sounds clearly in meetings
so sound does not travel through walls
 Sound systems for everyone
radio - CD players
mobile phones - iPods

29. 29
Physics is
everywhere
 From kitten’s ears to mobile phones