SOUNDS GOOD!

From musical boxes to iPods

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Space WalkAug 2005

Stephen Robinson

outside Discovery

NASA picture

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Can he call to those inside the space ship as he works?

NASA picture

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Connected to the space ship by a line

Why?

NASA picture

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Let’s play some games !

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Sound dance

The bunches move along the line. The children do not move along!

Sound moves this way

steps

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Sound travels to your ear

The air vibrates but does not travel from the alarm to the ear.

Sound

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Large ears to collect sound

Our ears are on the side of our heads.

We can play a game to find out why.

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?Why does Mittens look unhappy?

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Whales sing to each other.

Sound travels through water.

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Bush telephone

game Sound travels through the string

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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.

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Telephones -- The message travels through miles of

wires as an electrical signal.

microphone

loudspeaker

electrical signal

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Radio signal

Mobile phones use radio

Sound - electrical signal - radio signal - electrical signal - sound In one phone the sound is changed into an electrical signal then into a radio signal.

Sound - electrical signal - radio signal - electrical signal - sound

In the second phone the radio signal is changed into an electrical signal then into sound.

Mobile phone beacons

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What is this?

What sound does she make?

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What are these?

What sound do they make?

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What sound does this make?

How does it make the sound?

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Bells

What sounds will they make?

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Straw oboes

Listen as the straw is snipped.

blow

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Size matters!

Large things make

___________ sounds

Small things make

___________ sounds

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New words:

High pitch = high frequency

Low pitch = low frequency

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Size matters!

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What else changes sounds?

How do you tune a violin?

Let us try to make a string instrument.

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What have we learned? Vibrating objects make sounds

Sound needs a medium through which to travel – 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.

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Can you spot the baby?

Sound has lots of uses

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Ultrasound is very, very high frequency sound.

It is used to see inside people - to see

babies before they are born

if a heart is working well

blood flow

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Knowledge about sound helps - Musical instrument design

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 everyoneradio - CD players

mobile phones - iPods

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Physics is everywhere From kitten’s ears to mobile

phones