52 light reflection.ppt

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5. LIGHT

5.1 REFLECTION

a) PLANE MIRROR

b) CURVED MIRROR

i. CONCAVE MIRROR

ii. CONVEX MIRROR

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Pilihlah Aku (Bukan Bajuku)

Oi maknya, what scientific reasons these holes as I seen on ‘TV’?

Yes!… it’s a good idea,

To release heat just by lifting ‘our’ hands straight 180 degrees up,

To evaporate more sweat without showing my stomach to ‘you’

As a physical therapy to treat itchy at ‘your’ armpit.

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5. LIGHT

Normal

Incident ray

Reflected ray

i r

O

a) The Laws of Reflection:

5.1 Reflection of Light In a Plane Mirror

1. Angle of incidence, i = angle of reflection, r2. The incident and reflected rays and normal lie at the same plane

Mirror plane

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b) Type of Reflection

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c) The experiment to investigate the relationship between incidence angle, i and reflection angle, r

Power supply

Ray box

Paper

Plane mirrorNormal

5o

10o15o

25o

Protractor20o

ri

i o r o

5101520

25

ro

io

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Serupa, Ada Rupa tapi… Lebih Bodoh Rupanya!

Suddenly… I look somebody at a ‘window’. It is like an alien…I walk in fear to get nearer to it and it does look like me…Its face, like a ghost, Its body lousy, It smells very intoxicated..

But.. He does as what I do.

When my nose and ‘its’ nose ‘touch’ one another ..the alien ‘runs away’ very fast …where is it?

I laugh all day long, I never see the bad, mad, fool + crazy cat like that!..

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d) Position and Characteristics of the Image Formed by a PLANE mirror

Object distance, u Image distance, v

Object, O Image, I

ObserverMirror

Normal

Drawing the Ray Diagram The Characteristics of the Image:

1. Virtual (Can’t be form on a screen)

2. Laterally inverted3. Same size as the object4. The distance of image and object from the plane mirror are same

ir

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e) Experiment to find position and characteristics of an image by a plane mirror

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f) The Application of Plane Mirror in Our LifeState the examples application of Plane Mirror. State the characteristics of its image and the advantages.

1. Make-up Mirror

3. Mirror Periscope

4. Mirror in camera & OHP

2. Anti-parallax Mirror in an

Ammeter & Voltmeter

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Have you come to a Russian class ? Check this out with something that you stare every day in your bedroom.

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g) Reflection of Light in Convex and Concave Mirror

Compare the images formed by convex mirror and concave mirrorConvex Mirror Concave Mirror

Virtual VirtualDiminished Magnified

Erect Erect

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Concave MirrorConvex Mirror

Focal point

Focal point

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Principle Working of concave mirror and convex mirror

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Position and Characteristics of Images by Concave Mirror

ObjectNormal

Image

Object

Normal

Image

C F

C F

P

P

i) O > F

ii) O = C or O = 2F

1. Real (can form on screen)

2. Inverted3. Diminished4. Between F and C

1. Real2. Inverted3. Same size as object

4. At C

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ObjectC F ImageP

iii) O < F

What the characteristics of image?

1. Virtual (Can’t be form on screen)

2. Upright3. Magnified4. Behind the mirror

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Position and Characteristics of Images by Convex Mirror

ObjectNormal

CFP

What the characteristics of image?

Image

1. Virtual (Can’t be form on screen)2. Upright3. Diminished4. Between P and F, behind the mirror

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The Application of Convex Mirror and Concave Mirror in Ours Life

State the examples application of Convex Mirror and Concave Mirror. State the characteristics of its image and the advantages.

1. The Side Mirror and Rear-

view Mirror of a Car

3. A Surveillance Mirror

4. The Dentist’s mirror

2. A Blind Corner Mirror

5. Concave Reflector in torch

light and front lamp in a car

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Dentist’s mirror Concave Reflector in torch light

Concave Reflector in solar system

Rear- view Mirror of a Car

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> Incident ray from an object is reflected by the mirror to observer’s eyes.

> The angle of incidence = angle of reflection

> The image which is formed in the mirror is laterally inverted

Incidence ray

Normal

Rear-view Mirror

Observer

i = r

Reflection ray

Why the words ‘AMBULAN’ are wrote in laterally inverted?

The Answer:

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Oi..nak cari nahas ke? Orang lain pun nak hidup gak..! Ah..

‘PASSENGER’

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OK stop! .. Kita dah dapat ‘passenger’!