Science NATURE OF LIGHT: Reflection Properties of Light in Plane Mirror

At the end of this module,you are expected to:

• Explain the nature of light • Discuss the different types of reflection of light. • understand what are the laws of reflection

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INTRODUCTION

Everytime before we go out, we always look in the mirror to see and check ourselves, especially our faces and hairstyles, but have you noticed something special about you and your image when you look in the mirror? Have you also wondered how mirrors form images? And how is light reflected in the mirror? In this module, we'll try to answer all of these questions by knowing the nature of light regarding how a mirror creates an image and how light is reflected from the mirror.

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AUTOBIOGRAPHY My Name is Chloe C. Aure i am boy 16 years old and grade 10

student from dela paz high school 10 helios im born in dela paz pasig city and want to be successfull in future my goal is to be a good student and graduate this school year and my hobbies are playing basketball,online games and cleaning house when i am bored. John Carl R. Faundo Help Those Who Are Struggling And Continue Making Some Progress.

Cathlyn Joy T. Villaflores I have always dreamt of having a bakery shop, and that is why I study hard to have a successful academic status and to pursue my dreams of having my own bakery shop.

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Table of Contents Nature of Light Introduction……………………………………………………………… 2 Autobiography…………………………………………………………… 3 Reflection of Light in Mirrors………………………………………. 4 •Nature Of light • Reflection in Plane Mirror Characteristic Formed of By Plane Mirror • What Are The Laws Of Reflection Newtons and Cristiaan Huygens • The Tree Types Of Reflection Of Light Tree Laws of Reflection Wrap-Up…………………………………………………………………… 12 Post-Test…………………………………………………………………. 13 References…..................................................................... 14 Answer Key........................................................................15

LESSON Light is a transverse, electromagnetic wave that can be seen by the typical human. The wave nature of light was first illustrated through experiments on Diffraction and interference Like all electromagnetic waves, light can travel through a vacuum. The transverse Nature Of Light can be demonstrated through polarization. • Light is sometimes also known as visible light to contrast it from "ultraviolet light" and "infrared light". • Other forms of electromagnetic radiation that are not visible to humans are sometimes also known informally as "light" The speed of light in a vacuum… • is represented by the symbol c (from the Latin word celeritas, swiftness) • The symbol v used for the speed of light in a medium. • is equal to 299 792 458 m/s exactly, by definition • The value 3.00 × 108 m/s with three significant digits is precise enough for many applications. • is the universal speed limit • v < c for all meanings of the symbol v. • The speed of light in a medium (v) is always slower than the speed of light in a vacuum. • The difference is often negligible for low density media like air. • Faster than light communication appears to be impossible. • The speed of anything with mass (v) is always less than the speed of light in a vacuum. • Faster than light travel appears to be impossible. • is a universal constant • There are no known factors that affect the speed of light in a vacuum. • is also the speed of all other electromagnetic waves in a vacuum • The amplitude of a light wave is related to its intensity. • Intensity is the absolute measure of a light wave's power density.

• Brightness is the relative intensity as perceived by the typical human eye • The frequency of a light wave is related to its color. • Monochromatic light can be described by only one frequency. • Laser light is very nearly monochromatic. • There are six simple, named spectral colors in English each associated with a band of monochromatic light. In order of increasing frequency they are red, orange, yellow, green, blue, and violet. • The number of named spectral colors and their range of frequencies vary with culture and person. • Whether indigo (a color between blue and violet) should be considered a distinct spectral color is open to debate. • Light ranges in frequency from 385 THz on the red end to 790 THz on the violet end, where 1 THz = 1 terahertz = 1012 hertz. • Frequencies lower than 385 THz are said to be infrared (literally "below red").

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Frequencies higher than 790 THz are said to be ultraviolet (literally "beyond violet")

What is Reflection on a Plane Mirror? When the light rays get stroked on the flat mirror, they get reflected back. According to the laws of reflection, the angle of reflection is equal to the angle of incidence. The image is obtained behind the plane, which is present in the mirror. This process of obtaining a mirror image which is virtual and erect is known as a reflection on a plane mirror.

Characteristics of Image formed by Plane Mirror Following are the characteristics of an image formed by the plane mirror:

• The image obtained by the plane mirror is always erect and virtual. • The image size and the size of the object, both are equal. • The distance between the image obtained and the mirror is the same as the distance at which the object is placed. • Laterally inverted images are obtained.

What are the Laws of Reflection? The laws of reflection are divided into two main points and they are:

• The angle of incidence is equal to the angle of reflection. • The incident ray, reflected ray, and the normal at the point of incidence all lie in the same plane.

Newton’s Corpuscular Model of Light At an early age, Newton has always been interested in the theory of light. Newton's model of light proposes that propagation of light is caused by the rectilinear motion of light particles which he termed light corpuscles. These light particles travel at a finite speed and their interactions with the external environment e.g. rigid surfaces, walls and human eye, obey Newtonian physics. CHRISTIAAN HUYGENS

Based on the third theory, Huygens proposed that light traveled in waves through a rare substance called luminiferous ether. The waves of light allegedly vibrated the ether as they traveled from the object to the eye. With this as his foundation, Huygens calculated the laws of reflection and refraction.

There are Three Types Of Reflection Of Light Diffuse Reflection,Specular Reflection and Glossy Reflection.

Diffuse surfaces reflect (scatter) light in many angles.Diffuse reflection accounts for more of the color than any other type of distribution because most objects are opaque and reflect light diffusely.

Specular surfaces reflect light at the same as the angle at which the light strikes the surface.Specular reflection gives objects a glossy or mirror-like appearance.

Glossy surfaces are actually specular surfaces with micro surfaces at angles to surface plane.These micro surfaces reflect light not only specularly but also diffusely (at angles very close to the specular transmission), giving the surface a glossy appearance.

This bouncing of light rays is called reflection. There are two types of reflection, the specular reflection that occurs on materials with smooth surfaces like mirror and calm water, and diffused reflection which on the other hand occurs on materials with rough surfaces such as the wall or your book. These two obeys the Law of reflection which states that the angle of incidence is always equal to the angle of reflection.

The different types of reflection of light The reflection of light can Be roughly categorized into two types of reflection. Specular Reflection is defined as light reflected from a smooth surface at a definite angle, whereas diffuse reflection is produced by rough surfaces that tend to reflect light in all directions

There are 3 laws of reflection The First Law - The angle between the incident ray and the normal is equal to the angle between the reflected and ray and the normal. The Second Law - The incident ray, the normal ray and the reflected ray are all in the same plane. The Third Law - Incident ray and refracted ray are on different sides of the normal. Whenever we look into a mirror, or squint at sunlight glinting from a lake, we are seeing a reflection. When you look at this page, too, you are seeing light reflected from it. Large telescopes use reflection to form an image of stars and other astronomical objects.

The law of reflection states that the angle of reflection equals the angle of incidence— θr = θi. The angles are measured relative to the perpendicular to the surface at the point where the ray strikes the surface.

WRAP- UP

Eye

Plane mirror

Christiaan Huygens Laws of reflection

Specular Smooth plane mirror

smooth

Diffuse rough

light specular left right reversal

(1)________ Can be seen as a form of energy in the electromagnetic spectrum. This spectrum encompasses energy at different wavelengths, of which only a small portion ranging from roughly 380 to 780 nm can be perceived by the human (2)__________. (3)___________ a Dutch mathematician-astronomer who formulated the first detailed wave theory of light. (4)_________ states that the angle of incidence is equal to the angle of reflection. There are different types of mirrors. First is the (5)________ it is a mirror that, when the light hits an object, every part of the object reflects light in all directions. There are two types of reflections of light. First is the (6)________ or regular reflection. It is defined as light reflected from a (7)_______ surface at a definite angle, while the (8)_______ or irregular reflection is produced by (9)_________ surfaces that tend to reflect light in all directions. Also, when you view an image of yourself in a plane mirror, you will quickly notice that there is an apparent (10)_________ of an image

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POST-TEST 1.) It states that the angle of incidence is equal to the angle of reflection. a. Plane mirror

b. Light

c. Law’s of Refraction

d. Law’s of Reflection

2.) Your bathroom mirror can a. Plane mirror c. standard d. reflective

be

classified

as

a

______ b.

mirror. curved

3.) You raise your left hand in the mirror. You notice that the image that appears in the mirror is of your right hand. How it happened? a. Because of the left-right rule

b. Because of the mirror left-right reversal

c. Because of Mirror replacementd.

D.None of the above

4.) Light reflected from smooth surface a.Concave mirror b. Specular Reflection c. Convex mirror

at

definite

angle.

d. Diffuse Reflection

5.) is produced by _____ surfaces that tend to reflect light in all directions. a. Plane c.

b. Smooth

Rough

d.

Reflect

B. Direction: Arrange the jumbled letters to get the correct answer.

1. (WSLA FO ELRFCEITON ) is equal to the angle of reflection.

States that the angle of incidence

2. (LARSEPUC LARREGU FCEUTONELR) reflected from a smooth surface at a definite angle. 3. (FFIDDESU NOITCELFER) that tend to reflect light in all directions. 4. (XEVONC RRRIOM) mirror.

is defined as light

is produced by rough surface

Also known diverging mirror is a curved

5. (EAVCCON MRRRIO) Also known converging mirror has reflecting surface that is recessed in ward.

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References • https://leverageedu.com/blog/reflection-of-light/ • https://images.app.goo.gl/cY5zCqS7jMWAez768 • https://images.app.goo.gl/cY5zCqS7jMWAez768

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ANSWER KEY POST TEST

WRAP UP

A.

1.Light

1. C

2. A

2.Eye

3. B

4. B

3.Christiaan Huygens

5. D

4. Laws of reflection

B.

5.Plane Mirror

Plane mirror

6.Specular

laws of reflection

7.Smooth

Specular

8.Diffuse

diffuse

9.Rough

left right reversal

10.Left Right Reversal