1.2 Reflection Waves

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1.2 Analysing Reflection of Waves

What will happen to the waves after they hit

the retaining wall?

Reflect.


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4 phenomena of waves

2. Refractionof waves

1. Reflectionof waves

3. Diffractionof waves

4.Interferenceof waves


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Ripple Tan

Wavefront


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!"#$TI%&$!"#$TI%&$

To prevent refection rom occurring

To create water waves so thatwaves phenomena can be

investigate

What is the use of the rippleWhat is the use of the rippletank?tank?

Why do we need to use the sponge?Why do we need to use the sponge?

How are the imagesHow are the images

produced?produced?Name the instrument that can beName the instrument that can be

used to freeze the image of the waveused to freeze the image of the wave


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(ormation of waves pattern )sing Ripple tan

Pattern


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Reflectionof waves

is a phenomenonwhere allor part of the waves

are ret)rne+when they enco)ntera reflector


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1.wavelength-

2. fre)ency- f3. spee+- v

4. amplit)+e- a

/efore an+ after wave reflects

e)al

e)al

e)al

e)al

'.Direction of

propagation

of wave

change


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Diagram to show reflection of waves


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Incidentwaves

Planereflector

Reflectedwaves


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Reflectedwaves

Incidentwaves

NormalPlanereflector

Rules to draw reflection diagram


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reflector

i

r

Direction of

propagation ofinci+ent waves

Direction of

propagation of

reflecte+

waves

Inci+ent

waves

Reflecte+

wavesAngle of inci+ent

Angle of reflecte+


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1.3 Refractionof waves

Is a phenomenon

where there is changeof +irectionin the

propagationof waves

when they move from one me+i)mto another

me+i)m

+)e to changeof spee+


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1. wavelength

2.fre)ency- f

3.spee+- v

4.amplit)+e- a

e)al

lower

'.Direction of

propagation of

wave

towar+s

normal

$hallow area Depth areaWater waves

Denser

ol+ air

less +ense

hot air

$o)n+ waves-

5ight waves

shorter longer

e)al

higher

lower higher

away

normal


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Shallow

area

Refraction of Waves

Deep

areaDeep

area


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Shallow area

Deep area

Refraction of Waves

Deep area


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1.3 Refractionof waves


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Refraction of so)n+ waves

Warm +ay

#arth s)rface

8ot air

5ess +ense

ol+ air

Denser

9so)n+ wave travels

faster in hot air thancol+ air

9so)n+waverefracts away

from the earth

9layer of air near the

s)rface warmer

9layer of hot air less

+ense than layer of col+air

v

v


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ol+ night

Refraction of so)n+ waves

#arth s)rface

ol+ air

Denser

hot air

5ess +ense

9so)n+ wave travels

faster in hot air than

col+ air

9so)n+ wave refracts

towar+ earth

9layer of air near thes)rface cooler

9layer of col+ air

+enser than layer of hot

air

v

v


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hea+lan+

:ay /each

hea+lan+

hea+lan+

Deep

area

$hallow

area


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Refraction on water waves near a /each


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9Wavefront /en+ )ntil they almost tae the

o)tline of the shore

9Wavelength an+ spee+ +ecrease

9#nergy is sprea+ o)t thro)gh the /ay /each

9#nergy per part of /ay /each is less than

hea+lan+


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2'

1.4 Diffractionof waves

Is a phenomenonwhich waves sprea+o)tafter move thro)gha gapor o/stacle


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wavelength

fre)encyspee+

amplit)+e

/efore an+ after wave +iffracts

e)al

e)ale)al

hange +ecrease

Direction of

propagation

of wave

change


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2,

9When the wi+th of

the gap is

appro;imately the

wavelength-

the +iffracte+

waves sprea+ o)t

more

9When the wi+th of the

gap is wi+er thanwavelength-

the +iffracte+ waves

sprea+ o)t less


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9The narrower the gap-

the more the waves sprea+ o)t

9When the wi+th is appro;imately thewavelength- the +iffracte+ waves sprea+ o)t

more

9When the wi+th is wi+er than the

wavelength- the +iffracte+ waves sprea+

o)t less small +iffraction


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Diffraction of light waves

Diffraction pattern of light waves

Dar fringes :right fringes


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Diffraction of so)n+ waves

Why low fre)ency so)n+ waves are

+iffracte+ more than the high

fre)ency so)n+ waves ???????????


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Interference of waves


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a b

x

y z


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3'


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3*

>

a

< !

a

$)perposition of 2 crests


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a

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1.2 Reflection Waves