What is reflection ???????
The bouncing of light off a mirror surface is called reflection.
Types of reflection?????
There are two types of reflection --regular reflection , diffuse reflection.
--When a parallel beam of light hits a smooth surface,it would be reflected as a parallel beam .This is called regular reflection.
--When a beam of light hits a rough surface,the individual rays are reflectedin different directions,then no image formed .This types of reflection is called diffuse reflection.
Uses of reflection of light,examples?
Uses of plane mirrors -----
—— the rear of a view mirror of a car can helps to see traffic behind the car.
——plane mirrors on walls makes a room brighter.
——people use plane mirrors to check their appearance.
Uses of curved mirrors----
——security mirrors are used in shops.
——blind corner mirrors helped driver to see objects around the corner.
——a concave mirror is used to reflect light into microscope.
Acknowledgements:
----Explore your world with science discovery 2
-----http://images.google.cn/imgres?imgurl=http://id.mind.net/~zona/mstm/physics/light/rayOptics/reflection/r1.jpg&imgrefurl=http://id.mind.net/~zona/mstm/physics/light/rayOptics/reflection/reflection1.html&h=300&w=400&sz=14&hl=zh-CN&start=17&um=1&tbnid=vcnBWStV9c6jCM:&tbnh=93&tbnw=124&prev=/images%3Fq%3Dreflection%2Bof%2Blight%26um%3D1%26complete%3D1%26hl%3Dzh-CN%26rlz%3D1T4XNLA_zh-CNSG277SG277%26sa%3DX
Showing posts with label 2e3. Show all posts
Showing posts with label 2e3. Show all posts
Friday, June 20, 2008
Colours of Light by 2E1 Edgar Wong
How are colors produced?
Colors are produced when a light source hits a prism, which separates the white light into its separate colors are called dispersion.
How to get rainbow colors and to recombine the colors again?
Place a second prism positioned in a way that each other’s points are facing away from each other. Shine the light through both prisms.
What are primary colors?
The three primary colors are the minimum number of colors that can be mixed to make the greatest number of other colors. The primary colors cannot be made by mixing other colors.
Effects of mixing of colors.
When you mix colors together, you will get a different color. If you mix the three primary colors together, you get white.
What do you learn about that particular topic?
I’ve learn about the dispersion of white light by a prism and more about the primary colors.
Summarize the key points of that topic.
Colors, they are produced by white light hitting prisms, when lights separates its called dispersion. Placing two prisms facing away from each other can get and recombine colors. When mixing colors together, you get a different color.
Anything interesting to add?
The spectrum consists of: Red, Orange, Blue, Yellow, Green, Indigo and Violet.
Prisms separate the colors already present in the white light.
Credits.
Science Discovery, Rex M Heyworth, 128, 129 and 130, chapter 8
Color Mixing, Robert Truscio.
Colors are produced when a light source hits a prism, which separates the white light into its separate colors are called dispersion.
How to get rainbow colors and to recombine the colors again?
Place a second prism positioned in a way that each other’s points are facing away from each other. Shine the light through both prisms.
What are primary colors?
The three primary colors are the minimum number of colors that can be mixed to make the greatest number of other colors. The primary colors cannot be made by mixing other colors.
Effects of mixing of colors.
When you mix colors together, you will get a different color. If you mix the three primary colors together, you get white.
What do you learn about that particular topic?
I’ve learn about the dispersion of white light by a prism and more about the primary colors.
Summarize the key points of that topic.
Colors, they are produced by white light hitting prisms, when lights separates its called dispersion. Placing two prisms facing away from each other can get and recombine colors. When mixing colors together, you get a different color.
Anything interesting to add?
The spectrum consists of: Red, Orange, Blue, Yellow, Green, Indigo and Violet.
Prisms separate the colors already present in the white light.
Credits.
Science Discovery, Rex M Heyworth, 128, 129 and 130, chapter 8
Color Mixing, Robert Truscio.
Reflection of Light by 2E3 Siti Saiyidah Nafisah
I have learnt that reflection is the bouncing of light off a mirror. A plane mirror is a good reflector of light.
When a ray of light strikes the mirror at a right angle, it is reflected along the same path, called the normal. When a ray of light hits a plane mirror at an angle to the normal (called the angle of incidence), it is reflected at an equal angle but on the opposite side of the normal (angle of reflection). These two angles are always equal no matter how light rays strike the mirror. These are called The Law of Reflection.
In a plane mirror, the image is upright and of the same size as the object. In a plane mirror, the image lies as far behind the mirror as the object is in front of the mirror. Mirrors turn images around from left to right. Hence, in a plane mirror, an image is laterally inverted. An image that cannot be formed on a screen is called a virtual image. In a plane mirror, the image formed is always a virtual image.
There are two types of reflection- Regular reflection and Diffuse reflection.
Textbook Resource: Science Txtbk (pg119-121)
When a ray of light strikes the mirror at a right angle, it is reflected along the same path, called the normal. When a ray of light hits a plane mirror at an angle to the normal (called the angle of incidence), it is reflected at an equal angle but on the opposite side of the normal (angle of reflection). These two angles are always equal no matter how light rays strike the mirror. These are called The Law of Reflection.
In a plane mirror, the image is upright and of the same size as the object. In a plane mirror, the image lies as far behind the mirror as the object is in front of the mirror. Mirrors turn images around from left to right. Hence, in a plane mirror, an image is laterally inverted. An image that cannot be formed on a screen is called a virtual image. In a plane mirror, the image formed is always a virtual image.
There are two types of reflection- Regular reflection and Diffuse reflection.
Textbook Resource: Science Txtbk (pg119-121)
Colours of Light by 2E3 Nur Hasyimah
I’ve learned more about colours, such as the three primary colours, the secondary colours, and lastly, the rainbow. I find that learning about rainbows is the most interesting part of this topic.
Colour is a part of the human vision system. Colours derive from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors. Dispersion of light is the separation of splitting of white light into its separate colours.
The three primary colours are red, blue, and green. Primary colours are sets of colours that can be combined to make a useful range of colours. Mixing of pigments or dyes, such as in printing, the primaries normally used are magenta, cyan and yellow. A secondary colour is a colour made by mixing two primary colours in a given colour space. For example, yellow is a secondary colour because when you mix red and green, you will get yellow.
Rainbows cause a spectrum of light to appear in the sky when the sun shines onto droplets of moisture in the earth’s atmosphere. Rainbows consist of both the primary and the secondary colours. There are seven colours in a rainbow.
There are red, orange, yellow, green, blue, indigo and violet. Rainbows can also be caused by other forms of water than rain, including mist, spray, dew, fog and ice. Rainbows can have shapes other than a bow, including stripes, circles, or even flames. Rainbows can be seen whenever there are water drops in the air and sunlight shining from behind a person on the ground. They are commonly seen near waterfalls or fountains.
Resources:
http://en.wikipedia.org/wiki/Rainbows
http://en.wikipedia.org/wiki/Primary_colours
http://en.wikipedia.org/wiki/Secondary_colours
http://en.wikipedia.org/wiki/Colours
Colour is a part of the human vision system. Colours derive from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors. Dispersion of light is the separation of splitting of white light into its separate colours.
The three primary colours are red, blue, and green. Primary colours are sets of colours that can be combined to make a useful range of colours. Mixing of pigments or dyes, such as in printing, the primaries normally used are magenta, cyan and yellow. A secondary colour is a colour made by mixing two primary colours in a given colour space. For example, yellow is a secondary colour because when you mix red and green, you will get yellow.
Rainbows cause a spectrum of light to appear in the sky when the sun shines onto droplets of moisture in the earth’s atmosphere. Rainbows consist of both the primary and the secondary colours. There are seven colours in a rainbow.
There are red, orange, yellow, green, blue, indigo and violet. Rainbows can also be caused by other forms of water than rain, including mist, spray, dew, fog and ice. Rainbows can have shapes other than a bow, including stripes, circles, or even flames. Rainbows can be seen whenever there are water drops in the air and sunlight shining from behind a person on the ground. They are commonly seen near waterfalls or fountains.
Resources:
http://en.wikipedia.org/wiki/Rainbows
http://en.wikipedia.org/wiki/Primary_colours
http://en.wikipedia.org/wiki/Secondary_colours
http://en.wikipedia.org/wiki/Colours
Colours of light by 2E3 Neo Chin Yen
In this topic, I get to learn the combination and recombination of rainbow colours, and how the colours are being produced, and the effects of mixing all primary colours. I also learnt that colour is a function of the human visual system, and is not an intrinsic property.
Objects don't "have" color, they give off light that "appears" to be a color. Spectral power distributions exist in the physical world, but color exists only in the mind of the beholder.
Color is the perceptual quality of light.
The color of the light coming from an object has its origin in one or more of the following processes …
emission: the object itself is a source of light with a color determined by its spectra
reflection: certain frequencies are reflected from the object while others are not
transmission: certain frequencies are transmitted through the object while others are not
interference: certain frequencies are amplified by constructive interference while others are attenuated by destructive interference
dispersion: the angular separation of a polychromatic light wave by frequency during refraction
scattering: the preferential reradiation of certain frequencies of light striking small, dispersed particles
Something interesting I want to share are some historical junks.
The painter's color wheel is a historical artifact that refuses to die. The primary colors are not red, yellow, and blue. Painters and art teachers promote this scheme. It is a convenient way to understand how to mimic one color by mixing red, yellow, and blue. But these colors do not satisfy the definition of primary colors in that they can't reproduce the widest variety of colors when combined.
Cyan, magenta, and yellow have a greater chromatic range as evidenced by their ability to produce a reasonable black. No combination of red, yellow, and blue pigments will approach black as closely as do cyan, magenta, and yellow.
The website I got all my informations are from www.hypertextbook.com/physics/
Objects don't "have" color, they give off light that "appears" to be a color. Spectral power distributions exist in the physical world, but color exists only in the mind of the beholder.
Color is the perceptual quality of light.
The color of the light coming from an object has its origin in one or more of the following processes …
emission: the object itself is a source of light with a color determined by its spectra
reflection: certain frequencies are reflected from the object while others are not
transmission: certain frequencies are transmitted through the object while others are not
interference: certain frequencies are amplified by constructive interference while others are attenuated by destructive interference
dispersion: the angular separation of a polychromatic light wave by frequency during refraction
scattering: the preferential reradiation of certain frequencies of light striking small, dispersed particles
Something interesting I want to share are some historical junks.
The painter's color wheel is a historical artifact that refuses to die. The primary colors are not red, yellow, and blue. Painters and art teachers promote this scheme. It is a convenient way to understand how to mimic one color by mixing red, yellow, and blue. But these colors do not satisfy the definition of primary colors in that they can't reproduce the widest variety of colors when combined.
Cyan, magenta, and yellow have a greater chromatic range as evidenced by their ability to produce a reasonable black. No combination of red, yellow, and blue pigments will approach black as closely as do cyan, magenta, and yellow.
The website I got all my informations are from www.hypertextbook.com/physics/
Reflection of Light by 2E3 Elson Yeo
What is reflection of light?
When you look into a mirror, you see a picture of yourself. What you see is called an image. The image in a mirror is formed when light rays bounce off the mirror and travel to your eyes. This bouncing of light off a mirror is called reflection.
A flat mirror, called a plane mirror, is a good reflector of light. When a ray of light strikes the mirror at a right angle, it is reflected along the same path.
Scientists call this line the normal. When a ray of light hits a plane mirror at an angel to the normal, called the angel of incidence, it is reflected at an equal angle but on the opposite side of the normal, the angel of reflection. These two opposite side of the normal, the angle of reflection. The two angels are always equal no matter how light rays strike the mirror.
This generalization is called the law of reflection.
When does it happen?
When a ray of light hits a surface, it bounces off or reflects and then reaches our eyes. This phenomenon by which a ray of light changes the direction of propagation when it strikes a boundary between different media through which it cannot pass is described as the reflection of light
Types of reflection
There are two types of reflection – regular reflection and diffuse reflection.
When a parallel beam of light hits a smooth surface such as a plane mirror, it is reflected as a parallel beam. This is called regular reflection. An image is formed with regular reflection. That is, when we look at a smooth surface, we can see an image.
Most surfaces are actually quite rough. When a beam of light hits a rough surface, the individual rays are reflected in different directions. So no image is formed. This type of reflection is called diffuse reflection.
Uses of reflection of light and examples?
Convex mirrors are often used in shops as security mirrors because of the type of image produced by that mirror. The image is smaller but shows a wide angle view of the shop.
Concave mirrors are often used in torch lights or in the headlights of cars. The light travels in all directions from the light globe towards the mirror behind it. The rays are then reflected by the mirror and they form a beam of light (a bundle of parallel rays).
http://www.tutorvista.com/content/science/science-ii/reflection-light/reflection-light.php
http://www1.curriculum.edu.au/sciencepd/readings/ligh_reflection.htm
Textbook Page 119 , 121 & 122
When you look into a mirror, you see a picture of yourself. What you see is called an image. The image in a mirror is formed when light rays bounce off the mirror and travel to your eyes. This bouncing of light off a mirror is called reflection.
A flat mirror, called a plane mirror, is a good reflector of light. When a ray of light strikes the mirror at a right angle, it is reflected along the same path.
Scientists call this line the normal. When a ray of light hits a plane mirror at an angel to the normal, called the angel of incidence, it is reflected at an equal angle but on the opposite side of the normal, the angel of reflection. These two opposite side of the normal, the angle of reflection. The two angels are always equal no matter how light rays strike the mirror.
This generalization is called the law of reflection.
When does it happen?
When a ray of light hits a surface, it bounces off or reflects and then reaches our eyes. This phenomenon by which a ray of light changes the direction of propagation when it strikes a boundary between different media through which it cannot pass is described as the reflection of light
Types of reflection
There are two types of reflection – regular reflection and diffuse reflection.
When a parallel beam of light hits a smooth surface such as a plane mirror, it is reflected as a parallel beam. This is called regular reflection. An image is formed with regular reflection. That is, when we look at a smooth surface, we can see an image.
Most surfaces are actually quite rough. When a beam of light hits a rough surface, the individual rays are reflected in different directions. So no image is formed. This type of reflection is called diffuse reflection.
Uses of reflection of light and examples?
Convex mirrors are often used in shops as security mirrors because of the type of image produced by that mirror. The image is smaller but shows a wide angle view of the shop.
Concave mirrors are often used in torch lights or in the headlights of cars. The light travels in all directions from the light globe towards the mirror behind it. The rays are then reflected by the mirror and they form a beam of light (a bundle of parallel rays).
http://www.tutorvista.com/content/science/science-ii/reflection-light/reflection-light.php
http://www1.curriculum.edu.au/sciencepd/readings/ligh_reflection.htm
Textbook Page 119 , 121 & 122
Electricity by 2E3 Joevenn Ng
What Is Electricity?
Electricity is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable or non-renewable.
Source for this question: http://www.eia.doe.gov/kids/energyfacts/sources/electricity.html
How Is Electricity Produced?
Electricity generation - whether from fossil fuels, nuclear, renewable fuels, or other sources - is usually* based on the fact that "When magnets are moved near a wire, an electric current is generated in that wire."
"When magnets are moved near a wire, an electric current is generated in that wire."
Source for this question: http://hawaii.gov/dbedt/info/energy/renewable/electricitygeneration/
Uses Of Electricity.
Well electricity is widely used all around the world. They are used to do things like using a computer , charging of handphones and others. Electricity is used or all used for good and bad things.
Electricity is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable or non-renewable.
Source for this question: http://www.eia.doe.gov/kids/energyfacts/sources/electricity.html
How Is Electricity Produced?
Electricity generation - whether from fossil fuels, nuclear, renewable fuels, or other sources - is usually* based on the fact that "When magnets are moved near a wire, an electric current is generated in that wire."
"When magnets are moved near a wire, an electric current is generated in that wire."
Source for this question: http://hawaii.gov/dbedt/info/energy/renewable/electricitygeneration/
Uses Of Electricity.
Well electricity is widely used all around the world. They are used to do things like using a computer , charging of handphones and others. Electricity is used or all used for good and bad things.
Reflection of Light by 2E3 Ying jie
The bouncing of light off a mirror is called reflection.
Law of reflection
The ray of light approaching the mirror is known as the incident ray .The ray of light which leaves the mirror is known as the reflected ray .
At the point of incidence where the ray strikes the mirror, a line can be drawn perpendicular to the surface of the mirror, and this is called normal line.
The angle between the incident ray and the normal is known as the angle of incidence.
The angle between the reflected ray and the normal is known as the angle of reflection.
The law of reflection states that when a ray of light reflects off a surface THE ANGLE OF INCIDENCE = ANGLE OF REFLECTION .
Another law of reflection ,is Light travels in straight lines.
In a plane mirror ,
1. Image is Upright and of the same size of the object
2. Images lies as far behind the mirror as the object is in front of the mirror .
3. Image is laterally inverted .
4. image is always virtual image .
An image that cannot be formed on a screen is called VIRTUAL IMAGE.
Uses of the plane mirror,
Helps the driver to see the traffic behind , Makes room look bigger , Check their appearance .
Two types of reflection ,
Regular reflection – When a parallel beam of light hits a smooth surface , it is reflected as a parallel beam . An image is formed.
Diffuse reflection – When a beam of light hits the rough surface , individual rays are reflected in different directions. No image is formed .
Uses Of Curved mirrors ,
Convex Mirrors- Is a fish eye mirror or diverging mirror, is a curved mirror in which the reflective surface bulges toward the light source.
Upright images that are smaller than object. By the same time it allows many things to be seen.
Uses of Convex Mirrors :
1.Camera phones use convex mirrors to allow the user correctly aim the camera while taking a self-portrait.
2.The passenger-side mirror on a car is typically a convex mirror. It gives a safety warning "Objects in mirror are closer than they appear", to warn the driver of the convex mirror's distorting effects on distance perception.
Concave mirrors – Upright magnified images if the object is close to the mirror . If it is further away , the image is inverted .
Uses of Concave Mirrors :
Dentist mirror magnifies the image of our teeth .
Used to reflect light into microscope.
Law of reflection
The ray of light approaching the mirror is known as the incident ray .The ray of light which leaves the mirror is known as the reflected ray .
At the point of incidence where the ray strikes the mirror, a line can be drawn perpendicular to the surface of the mirror, and this is called normal line.
The angle between the incident ray and the normal is known as the angle of incidence.
The angle between the reflected ray and the normal is known as the angle of reflection.
The law of reflection states that when a ray of light reflects off a surface THE ANGLE OF INCIDENCE = ANGLE OF REFLECTION .
Another law of reflection ,is Light travels in straight lines.
In a plane mirror ,
1. Image is Upright and of the same size of the object
2. Images lies as far behind the mirror as the object is in front of the mirror .
3. Image is laterally inverted .
4. image is always virtual image .
An image that cannot be formed on a screen is called VIRTUAL IMAGE.
Uses of the plane mirror,
Helps the driver to see the traffic behind , Makes room look bigger , Check their appearance .
Two types of reflection ,
Regular reflection – When a parallel beam of light hits a smooth surface , it is reflected as a parallel beam . An image is formed.
Diffuse reflection – When a beam of light hits the rough surface , individual rays are reflected in different directions. No image is formed .
Uses Of Curved mirrors ,
Convex Mirrors- Is a fish eye mirror or diverging mirror, is a curved mirror in which the reflective surface bulges toward the light source.
Upright images that are smaller than object. By the same time it allows many things to be seen.
Uses of Convex Mirrors :
1.Camera phones use convex mirrors to allow the user correctly aim the camera while taking a self-portrait.
2.The passenger-side mirror on a car is typically a convex mirror. It gives a safety warning "Objects in mirror are closer than they appear", to warn the driver of the convex mirror's distorting effects on distance perception.
Concave mirrors – Upright magnified images if the object is close to the mirror . If it is further away , the image is inverted .
Uses of Concave Mirrors :
Dentist mirror magnifies the image of our teeth .
Used to reflect light into microscope.
Reflection of Light by 2E3 Li Yanbing
1) WHAT IS REFLECTION OF LIGHT?
The bouncing of light off a mirror is called reflection.
2) WHEN DOES IT HAPPEN?
Reflection happen when the image in a mirror is formed when light rays bounce off the mirror and travel to your eyes.
3) TYPES OF REFLECTION
There are basically two types of reflection:
Regular Reflection
When a parallel beam of light hits a smooth surface such as a plane mirror, it is reflected as a parallel beam. This is called a REGULAR reflection.That is when we look at a smooth surface,we see an image.
Diffuse Reflection
When a beam of light hits a rough surface, the individual rays are reflected in different direction. So no image is formed. This type of reflection is called DIFFUSE reflection.
4) USE OF REFLECTION OF LIGHT; EXAMPLES.
There are many examples of the use of reflection of light.
The rear view mirror of a car helps drivers to see traffic behind the car.
The use of plane mirrors to check one’s appearance.
Periscopes are made of two plane mirrors which see over obstacles such as walls.
Mirrors used in double-deck buses to help the driver to see the passengers on the upper deck.
Sources:
Heyworth, Rex M. Explore Your World with Science Discovery 2.
Diagram obtained from <http://www.rebeccapaton.net/rainbows/rflctn.gif>
The bouncing of light off a mirror is called reflection.
2) WHEN DOES IT HAPPEN?
Reflection happen when the image in a mirror is formed when light rays bounce off the mirror and travel to your eyes.
3) TYPES OF REFLECTION
There are basically two types of reflection:
Regular Reflection
When a parallel beam of light hits a smooth surface such as a plane mirror, it is reflected as a parallel beam. This is called a REGULAR reflection.That is when we look at a smooth surface,we see an image.
Diffuse Reflection
When a beam of light hits a rough surface, the individual rays are reflected in different direction. So no image is formed. This type of reflection is called DIFFUSE reflection.
4) USE OF REFLECTION OF LIGHT; EXAMPLES.
There are many examples of the use of reflection of light.
The rear view mirror of a car helps drivers to see traffic behind the car.
The use of plane mirrors to check one’s appearance.
Periscopes are made of two plane mirrors which see over obstacles such as walls.
Mirrors used in double-deck buses to help the driver to see the passengers on the upper deck.
Sources:
Heyworth, Rex M. Explore Your World with Science Discovery 2.
Diagram obtained from <http://www.rebeccapaton.net/rainbows/rflctn.gif>
Colours of Light by 2E3 Mageshwary
In this topic I learned about colours, what causes the colours in a rainbow, what is a spectrum, what is called dispersion, what are the seven main colours of the visible spectrum, what are the primary colours and the mixing of colours.
The key points of this topic are, a spectrum is a band of colours. The rainbow is a spectrum of white (ordinary) light into its component colours, white light can be dispersed using a prism, the spectrum of white light consist of seven colours: red, orange, yellow, green, blue, indigo, and violet,
The colours of the spectrum can be recombined to give white light, rainbows are formed by the dispersion of white light by raindrops,
red, green and blue are the primary colours of light, white light can be combined by mixing red, green and blue lights, a colour filter is clear plastic or glass that lets through some colours but absorbs the others, a red filter allows red light to pass through, an object has an certain colour because it reflects light of that colour and absorbs light of other colours.
The interesting things are that a prism can be used to break apart white light into its component colours. This shows that white light is a mixture of the projected colours.
Although the spectrum shows that white light contains a continuous rage of colours, colours from just three areas of the spectrum could be mixed to form any other colour including white. These three colours of light are from the red, green and blue parts of the spectrum. When the three primary colours of light is being added. This can be seen where the primary colour illumination over laps. The yellow formed when red light is added to green light is equal to the illumination of the red and green combined.
This information is taken from the school science text book and,http://home.att.net/~B-P.TRUSIO/COLOR.htm
The key points of this topic are, a spectrum is a band of colours. The rainbow is a spectrum of white (ordinary) light into its component colours, white light can be dispersed using a prism, the spectrum of white light consist of seven colours: red, orange, yellow, green, blue, indigo, and violet,
The colours of the spectrum can be recombined to give white light, rainbows are formed by the dispersion of white light by raindrops,
red, green and blue are the primary colours of light, white light can be combined by mixing red, green and blue lights, a colour filter is clear plastic or glass that lets through some colours but absorbs the others, a red filter allows red light to pass through, an object has an certain colour because it reflects light of that colour and absorbs light of other colours.
The interesting things are that a prism can be used to break apart white light into its component colours. This shows that white light is a mixture of the projected colours.
Although the spectrum shows that white light contains a continuous rage of colours, colours from just three areas of the spectrum could be mixed to form any other colour including white. These three colours of light are from the red, green and blue parts of the spectrum. When the three primary colours of light is being added. This can be seen where the primary colour illumination over laps. The yellow formed when red light is added to green light is equal to the illumination of the red and green combined.
This information is taken from the school science text book and,http://home.att.net/~B-P.TRUSIO/COLOR.htm
Reflection of Light by 2E3 Rachel Ng
The ray of light which strikes the surface is called the incident ray.
The ray of light which leaves the surface is called the reflected ray.
A line perpendicular to the surface is imagined at the point of reflection. This line is called a normal. And when a ray of light strikes the mirror at a right angle,it is reflected along the same path.
When a ray of light hits a plane mirror at an angle to the normal(called the angle of incident), it is reflected at an equal angle but on the opposite side of the normal(angle of reflection).these two angles are always equal no matter how light rays strike the mirror.
A flat mirror,called plane mirror,is a good reflector of light.
WHAT IS REFLECTION OF LIGHT??
ANS:Reflection is the bouncing off light after hitting a mirror surface.
WHEN DOES IT HAPPEN?
ANS:it happen when the light travel and bounce off after hitting a mirror surface:)
IMAGES IN A PLANE MIRROR
In a plane mirror:
The image is upright
And the image is also of the same size as the object.
The image lies far behind the mirror
But the object is in front of the mirror.
The image is also laterally inverted in a plane mirror.
(Laterally inverted = opposite side)
The image formed is always a virtual image.
(virtual = cannot be capture on screen)
TYPE OF REFLECTION
REGULAR REFLECTION!!
When a parallel beam of light hits a smooth surface such as a plane mirror, it is reflected as a parallel beam. This is called regular reflection. An image is formed with regular reflection. That is. When we look at a smooth surface,we can see an image.
Regular reflection takes place when a parallel beam of light strikes a smooth polished surface and it is reflected back as a parallel beam of light. Reflection from mirror and metallic surface are example of regular reflection.
Regular reflection
On a smooth surface,a parallel beam of light is reflected as a parallel beam.
An image is formed.
DIFFUSE REFLECTION!!
Most surfaces, are usually quite rough. When a beam of light hits a rough surface,the individual rays are reflected in different directions. So no image is formed. This type of reflection is called diffuse reflection.
Diffuse reflection or irregular reflection takes place when a parallel beam of light strikes a rough surface and it is reflected back in different random directions reflected from object such as trees and are example of diffused reflection.
Diffuse reflection
On a rough surface.
A parallel beam of light is reflected as individual rays reflected in different directions
No image is formed.
USES OF PLANE MIRRORS!!
uses of plane mirror:
Help a driver see the traffic behind.
Helps a person check appearance.
Makes s room appear bigger.
USES OF CURVE MIRROR!!
Curve surface can also act as mirrors. Curved mirror can be convex(like the back of a spoon) or concave(like the front of a spoon).The images formed by these mirror are different from those formed by plane mirror. Convex mirror form upright images that are always smaller than the object. They also have large “field of view” ,that is, they allow many thing to be seen.
USES OF CURVE MIRROR!!
Convex mirrors from upright image that are always smaller than the object, They allow many thing to be seen.
Concave mirror form upright magnified if the object is close to the mirror. If the image is further away,the image is inverted.
RESOURSE!!
http://www.google.com.sg/search?hl=en&q=convex+mirror&meta=
http://www.google.com/
Explore your world with science discovery 2 textbook
Electricity by 2E3 Serene Pang
What is electricity?
Electricity is a naturally occurring force that exists all around us.
How is electricity being produced?
Electricity energy comes from 2 main sources. These are mains electricity and electricity cells.
Main electricity is generated in power stations. The plugs of electrical appliances are inserted into main sockets to obtain this electricity.
Electric cells give out only a little energy. They are called batteries.
What is current?
An electric current is the flow of electrons in one direction in a circuit. We use an ammeter to the size of the electric current. The SI unit for electric current is the ampere (A). The picture shows a ammeter.
What is voltage?
Voltage is a measure of how much energy the electrons receive. To measure voltage, we use voltmeter. The SI unit for voltage is the volt (V). The picture shows a voltmeter.
Uses of electricity
Electricity is the most widely used type of energy in the world. We use it for work and for play, in the home and at work. In the past it mainly provided us with light and heat. Nowadays, the number of electronic appliances has hugely increased, we now use it almost everyday. We also use it for daily applications such as light, fan, etc. It also improves our lives.
Source obtained from textbooks, http://www.teachnet.ie/pcoakley/consumers.htm,
Electricity is a naturally occurring force that exists all around us.
How is electricity being produced?
Electricity energy comes from 2 main sources. These are mains electricity and electricity cells.
Main electricity is generated in power stations. The plugs of electrical appliances are inserted into main sockets to obtain this electricity.
Electric cells give out only a little energy. They are called batteries.
What is current?
An electric current is the flow of electrons in one direction in a circuit. We use an ammeter to the size of the electric current. The SI unit for electric current is the ampere (A). The picture shows a ammeter.
What is voltage?
Voltage is a measure of how much energy the electrons receive. To measure voltage, we use voltmeter. The SI unit for voltage is the volt (V). The picture shows a voltmeter.
Uses of electricity
Electricity is the most widely used type of energy in the world. We use it for work and for play, in the home and at work. In the past it mainly provided us with light and heat. Nowadays, the number of electronic appliances has hugely increased, we now use it almost everyday. We also use it for daily applications such as light, fan, etc. It also improves our lives.
Source obtained from textbooks, http://www.teachnet.ie/pcoakley/consumers.htm,
Reflection of Light by 2E3 Syafiq
I learnt the definition of reflection, the law of reflection, the characteristic of the image formed in a mirror, the different types of reflection, the uses of plain mirrors and curved mirrors and drawing the reflection of diagram during physics lessons.
Definition of reflection: When light rays bounce off the mirror and travel to your eyes.
The law of reflection: The angle of incidence is equal to the angle of reflection.
The characteristic of the image formed in a mirror:
- The image formed in a plane mirror is virtual, laterally inverted, upright, same size as the object and the image lies far behind the mirror as the object is in front of the mirror.
The different types of reflection:
( Regular reflection )
When a parallel beam of light hits a smooth surface such as a plane mirror, it is reflected as a parallel beam.
( Diffuse reflection ) When a beam of light hits a rough surface, the individual rays are reflected in different direction and no image is formed.
Uses of plane mirror: It helps the driver to see traffic behind the car, it make a room look bigger and to check the person appearance.
Uses of curved mirror:
(Convex mirror) Convex mirrors form upright images that are always smaller than the object. (e.g. security mirrors are used in shop)
(Concave mirror) Concave mirrors form upright magnified images if the object is close to the mirror. If the object is further away, the image is inverted. (e.g. tool used by dentist)
Resources: http://images.google.com.sg/ and Science Discovery Science textbook 2.
Thursday, June 19, 2008
Reflection of Light by 2E3 Zay Nyein
I have learn the definition of reflection, the law of reflection , the characteristic of the image formed in mirror, the different types of reflection, the uses of plane mirror and the two different types of curved mirror.
Reflection is the bouncing of light off a mirror and travel to your eyes. The law of reflection: The angle of incidence is equal to the angle of reflection. The image formed in a plane mirror is virtual, upright, laterally inverted, same size as the object and as far behind the mirror as the object is in front of the mirror.
There are two different types of reflection (1) Regular reflection and (2) Diffuse reflection. When the parallel beam of light hits a smooth surface, it is reflected as a parallel beam and the image is formed is called Regular reflection. When a beam of light hits a rough surface, the individual rays are reflected in different directions and the image is not formed is called Diffuse reflection.
The three uses of plane mirror
(1) helps the driver to check the traffic behind
(2) makes a room look bigger and
(3) check the person appearance.
The two different types of curved mirror (1) Concave mirror and (2) Convex mirror.
Concave mirror form upright magnified images if the object is close to the mirror. If the object is further away, the image is inverted e.g. used by dentist to check the teeth.
Convex mirror form upright images that always smaller than the object e.g. security mirrors are used in shops.
Resources
http://images.google.com.sg/ and the Science Discovery 2 (Text book)
Resources
http://images.google.com.sg/ and the Science Discovery 2 (Text book)
Reflection of Light by 2E3 Jocelyn Lee
After my group and I finished doing the project we has chosen to do( reflection of light), i have learnt how to build good team work with my group members.
I know understand and know more about the reflection of light through this project, such as the law of reflection.
The behavior of the light as it reflects would follow a predictable law known as the law of reflection. Diagrams are use to illustrates the law of reflection. An example of it is:
The ray of light which strikes on the surface is called the incident ray. The ray of light which leaves the surface is called the reflected ray. A line perpendicular to the surface is imagined at the point of reflection the line is called a normal. The angle between the incident ray and the normal is called the angle of incidence. The angle between the reflected ray and the normal is called the angle of reflection.
To summarize,THE ANGLE OF REFLECTION IS EQUAL TO THE ANGLE OF INCIDENCE.
Resources: http://id.mind.net/~zona/mstm/physics/light/rayOptics/reflection/reflection1.html
I know understand and know more about the reflection of light through this project, such as the law of reflection.
The behavior of the light as it reflects would follow a predictable law known as the law of reflection. Diagrams are use to illustrates the law of reflection. An example of it is:
The ray of light which strikes on the surface is called the incident ray. The ray of light which leaves the surface is called the reflected ray. A line perpendicular to the surface is imagined at the point of reflection the line is called a normal. The angle between the incident ray and the normal is called the angle of incidence. The angle between the reflected ray and the normal is called the angle of reflection.
To summarize,THE ANGLE OF REFLECTION IS EQUAL TO THE ANGLE OF INCIDENCE.
Resources: http://id.mind.net/~zona/mstm/physics/light/rayOptics/reflection/reflection1.html
Reflection of Light by 2E3 Kho Wei Xian
After the first semester, I have learnt a lot of thing about the reflection of light. The law of reflection, the types of reflection, uses of mirrors and image in a plane mirror.
Reflection is the bouncing off light after hitting a mirror surface. The reflection of light can be represented by the reflected diagram. A plane mirror is a good reflector of light. The ray of light approaching the mirror is known as the incident ray (labeled i in the diagram). The ray of light which leaves the mirror is known as the reflected ray (labeled r in the diagram). At the point of incidence where the ray strikes the mirror, a line can be drawn perpendicular to the surface of the mirror. This line is known as a normal line. (labelled N in the diagram)
The normal line divides the angle between the incident ray and the reflected ray into two equal angles. The angle between the incident ray and the normal is known as the angle of incidence. The angle between the reflected ray and the normal is known as the angle of reflection. When a ray of light hit a plane mirror and when the light is reflected, the angle of incidence and the angle of reflection is the same. This is called the law of reflection.
I also learnt that in a plane mirror,
The image formed is upright and it is the same size as the object,
The image lies far behind the mirror as the object is in front of the mirror,
The image is laterally inverted
The image is virtual(It cannot be captured on the screen)
There are two types of reflection, Regular and Diffuse reflection.
Regular reflection is when parallel beam of light hits a smooth surface and is reflected as a parallel beam.
Diffuse reflection is when a beam of light hits a rough surface, the individual ray are reflected in different directions. There is image formed in Regular reflection and there is no image formed in Diffuse reflection.
I also learnt the uses of the mirrors. There are three types of mirrors, Plane mirrors, and Convex, Concave mirrors which are under Curved mirrors.
Plane mirrors helps the driver to see traffic behind, make a room appear bigger and let a person check their appearance.
Convex mirrors form upright images that are always smaller than the object. They also allow many things to be seen. Convex mirrors are used in shops for security reasons, and also helps the drivers to see object around the corner.
Concave mirrors form upright magnified images if the object is close to the mirror. The image I inverted if the object is further away. Concave mirrors are used to reflect light into a microscope and help the dentists to check teeth conditions.
I have also found out that other than Regular and Diffuse reflection, there are other types of reflection such as Retro reflection, Complex conjugate reflection, Neutron reflection, Sound reflection, Seismic reflection.
Acknowledgements: http://www.glenbrook.k12.il.us/GBSSCI/PHYS/Class/refln/u13l1c.html
http://en.wikipedia.org/wiki/Reflection_(physics)
Explore Your World With Science Discovery 2
Done By: KHO WEI XIAN (25)
Reflection is the bouncing off light after hitting a mirror surface. The reflection of light can be represented by the reflected diagram. A plane mirror is a good reflector of light. The ray of light approaching the mirror is known as the incident ray (labeled i in the diagram). The ray of light which leaves the mirror is known as the reflected ray (labeled r in the diagram). At the point of incidence where the ray strikes the mirror, a line can be drawn perpendicular to the surface of the mirror. This line is known as a normal line. (labelled N in the diagram)
The normal line divides the angle between the incident ray and the reflected ray into two equal angles. The angle between the incident ray and the normal is known as the angle of incidence. The angle between the reflected ray and the normal is known as the angle of reflection. When a ray of light hit a plane mirror and when the light is reflected, the angle of incidence and the angle of reflection is the same. This is called the law of reflection.
I also learnt that in a plane mirror,
The image formed is upright and it is the same size as the object,
The image lies far behind the mirror as the object is in front of the mirror,
The image is laterally inverted
The image is virtual(It cannot be captured on the screen)
There are two types of reflection, Regular and Diffuse reflection.
Regular reflection is when parallel beam of light hits a smooth surface and is reflected as a parallel beam.
Diffuse reflection is when a beam of light hits a rough surface, the individual ray are reflected in different directions. There is image formed in Regular reflection and there is no image formed in Diffuse reflection.
I also learnt the uses of the mirrors. There are three types of mirrors, Plane mirrors, and Convex, Concave mirrors which are under Curved mirrors.
Plane mirrors helps the driver to see traffic behind, make a room appear bigger and let a person check their appearance.
Convex mirrors form upright images that are always smaller than the object. They also allow many things to be seen. Convex mirrors are used in shops for security reasons, and also helps the drivers to see object around the corner.
Concave mirrors form upright magnified images if the object is close to the mirror. The image I inverted if the object is further away. Concave mirrors are used to reflect light into a microscope and help the dentists to check teeth conditions.
I have also found out that other than Regular and Diffuse reflection, there are other types of reflection such as Retro reflection, Complex conjugate reflection, Neutron reflection, Sound reflection, Seismic reflection.
Acknowledgements: http://www.glenbrook.k12.il.us/GBSSCI/PHYS/Class/refln/u13l1c.html
http://en.wikipedia.org/wiki/Reflection_(physics)
Explore Your World With Science Discovery 2
Done By: KHO WEI XIAN (25)
Colours of Light by 2E3 Ho Zong Hua
Dispersion of White Light and How are colours produced
Sunlight may appear white, but it is actually made up of a mixture of seven colours. When the sunlight passes through the raindrops, the raindrops split the sunlight into a range or a spectrum of colours. The colours that make up the spectrum are red, orange, yellow, green, blue, indigo and violet. The spitting of white light into a range or a spectrum is called the dispersion of white light.
Dispersion of White Light and How are colours produced
When a beam of white light enters a prism, it slows down and is refracted. The white light is then split into seven different visible colours of light. Which are red, orange, yellow, green, blue, indigo and violet. The seven different colours of light, which make up white light, slow down at different rates. In other words, the different colours of light are refracted or bent at different angles.
Point 2
How to get rainbow colours and to recombine it again
What is primary colours
What are the effects of mixing colours
As the refracted colours of light leave the prism, they are bent again, but not in their original paths. This is because the face of the prism through which the light leaves is not parallel to the face through which it enters.
To prove that white light is a mixture of different colours, another prism can be used to recombine the colours of its spectrum.
Another way of combining the different colours of spectrum is by spinning a rainbow-coloured disc called Newton’s disc.
Primary colours are green, red and blue; these three colours when mixed will form the white light.
Cyan, yellow and magenta are called secondary colours. They are produced by mixing any two of the three primary colours.
Cyan = blue + green
Yellow = red + green
Magenta = red + blue
Mixing all the three primary colours will give the white light
Red + blue + green = white
By using different brightness we can create all the colours of the rainbow and many other colours that go to make up our multicolored world.
Sunlight may appear white, but it is actually made up of a mixture of seven colours. When the sunlight passes through the raindrops, the raindrops split the sunlight into a range or a spectrum of colours. The colours that make up the spectrum are red, orange, yellow, green, blue, indigo and violet. The spitting of white light into a range or a spectrum is called the dispersion of white light.
Dispersion of White Light and How are colours produced
When a beam of white light enters a prism, it slows down and is refracted. The white light is then split into seven different visible colours of light. Which are red, orange, yellow, green, blue, indigo and violet. The seven different colours of light, which make up white light, slow down at different rates. In other words, the different colours of light are refracted or bent at different angles.
Point 2
How to get rainbow colours and to recombine it again
What is primary colours
What are the effects of mixing colours
As the refracted colours of light leave the prism, they are bent again, but not in their original paths. This is because the face of the prism through which the light leaves is not parallel to the face through which it enters.
To prove that white light is a mixture of different colours, another prism can be used to recombine the colours of its spectrum.
Another way of combining the different colours of spectrum is by spinning a rainbow-coloured disc called Newton’s disc.
Primary colours are green, red and blue; these three colours when mixed will form the white light.
Cyan, yellow and magenta are called secondary colours. They are produced by mixing any two of the three primary colours.
Cyan = blue + green
Yellow = red + green
Magenta = red + blue
Mixing all the three primary colours will give the white light
Red + blue + green = white
By using different brightness we can create all the colours of the rainbow and many other colours that go to make up our multicolored world.
Reflection of Light by 2E3 Lim Jun Jie
Reflection of light
What is reflection of light?
Reflection of light is, light rays bounce of the mirror and travel to your eyes, this bouncing of light off a mirror is called reflection.
When does it happen?
Reflection of light (and other forms of electromagnetic radiation) occurs when the waves encounter a surface or other boundary that does not absorb the energy of the radiation and bounces the waves away from the surface.
Types of reflection.
Diffuse reflection
When light strikes a rough or granular surface, it bounces off in all directions due to the microscopic irregularities of the interface. Thus, an 'image' is not formed. This is called diffuse reflection. The exact form of the reflection depends on the structure of the surface.
Retro reflector
A simple retro reflector can be made by placing three ordinary mirrors mutually perpendicular to one another (a corner reflector). The image produced is the inverse of one produced by a single mirror. A surface can be made partially retro reflective by depositing a layer of tiny refractive spheres on it or by creating small pyramid like structures. In both cases internal reflection causes the light to be reflected back to where it originated. In this application perfect retro reflection is not desired, since the light would then be directed back into the headlights of an oncoming car rather than to the driver's eyes
Complex conjugate reflection
Light bounces exactly back in the direction from which it came due to a nonlinear optical process. In this type of reflection, not only the direction of the light is reversed, but the actual wave fronts are reversed as well.
Uses of reflection of light, examples?
Some uses of reflection is for people to check their appearance a mirror at home, allow drivers to see the traffic behind the car a rear view mirror, to allow owners of shops to see angles of their shops which they can’t see a security mirror, magnifies image a dentist mirror.
Adapted from:
http://en.wikipedia.org/wiki/Reflection_(physics)
http://micro.magnet.fsu.edu/primer/lightandcolor/reflectionintro.html
What is reflection of light?
Reflection of light is, light rays bounce of the mirror and travel to your eyes, this bouncing of light off a mirror is called reflection.
When does it happen?
Reflection of light (and other forms of electromagnetic radiation) occurs when the waves encounter a surface or other boundary that does not absorb the energy of the radiation and bounces the waves away from the surface.
Types of reflection.
Diffuse reflection
When light strikes a rough or granular surface, it bounces off in all directions due to the microscopic irregularities of the interface. Thus, an 'image' is not formed. This is called diffuse reflection. The exact form of the reflection depends on the structure of the surface.
Retro reflector
A simple retro reflector can be made by placing three ordinary mirrors mutually perpendicular to one another (a corner reflector). The image produced is the inverse of one produced by a single mirror. A surface can be made partially retro reflective by depositing a layer of tiny refractive spheres on it or by creating small pyramid like structures. In both cases internal reflection causes the light to be reflected back to where it originated. In this application perfect retro reflection is not desired, since the light would then be directed back into the headlights of an oncoming car rather than to the driver's eyes
Complex conjugate reflection
Light bounces exactly back in the direction from which it came due to a nonlinear optical process. In this type of reflection, not only the direction of the light is reversed, but the actual wave fronts are reversed as well.
Uses of reflection of light, examples?
Some uses of reflection is for people to check their appearance a mirror at home, allow drivers to see the traffic behind the car a rear view mirror, to allow owners of shops to see angles of their shops which they can’t see a security mirror, magnifies image a dentist mirror.
Adapted from:
http://en.wikipedia.org/wiki/Reflection_(physics)
http://micro.magnet.fsu.edu/primer/lightandcolor/reflectionintro.html
Electricity by 2E3 Bernard Kay
What is electricity
Electricity is a form of energy.It is very convenient because it can be changed to other forms of energy.Electrical energy is changed to sound energy in radios,to heat energy in rice cookers and to kinetic energy in radios,to heat energy in rice cookers and to kinetic energy in electric fans.
How is electricity produced
Electricity is produced generated in power stations.The plugs of the electrical appliances are inserted into mains sockets to obtain this electricity.Main electricity supplies a lot of energy.It can give us an electric shock which can kill us.
Electricity can also be produced from fossil fuels,hydro dams,static electricity.
Uses of electricity
Electricity is used to power up our daily usage such as.Computers,lamps,air conditioning,furnace,water heater
Electricity is a form of energy.It is very convenient because it can be changed to other forms of energy.Electrical energy is changed to sound energy in radios,to heat energy in rice cookers and to kinetic energy in radios,to heat energy in rice cookers and to kinetic energy in electric fans.
How is electricity produced
Electricity is produced generated in power stations.The plugs of the electrical appliances are inserted into mains sockets to obtain this electricity.Main electricity supplies a lot of energy.It can give us an electric shock which can kill us.
Electricity can also be produced from fossil fuels,hydro dams,static electricity.
Uses of electricity
Electricity is used to power up our daily usage such as.Computers,lamps,air conditioning,furnace,water heater
Reflection of Light by 2E3 Fong Lai Guan
WHAT IS REFLECTION OF LIGHT?
Reflection of light is light ray that neither transmitted nor absorbed, but bounced back to our eyes from the surface of the medium they encounter. This happened when incident ray approaches a surface of a reflecting medium, such as a mirror, this ray is then bounces back as reflected ray.
TYPE OF REFLECTION
There are three of reflections. They are diffuse, mirror and retort reflection.
Diffuse reflection occurs when light strikes rough surface such as clothing and foliage. These surfaces cause the light to scatter in all direction. No reflection formed.
Mirror reflection occurs when light strikes surface that are smooth and glossy. The light reflects off the surface at an equal, but opposite angle to the source. Reflection is formed.
Retort reflection occurs when surfaces return a portion of directed light back to its source.
USES OF REFLECTION
For looking at yourself, making look bigger than it suppose to and checking of shoplifter etc.
I learn that there are more to learn from the internet than the textbook. The information the textbook is too limited.
Information from:http://www.tpub.com/neets/tm/106-3.htm
Reflection of light is light ray that neither transmitted nor absorbed, but bounced back to our eyes from the surface of the medium they encounter. This happened when incident ray approaches a surface of a reflecting medium, such as a mirror, this ray is then bounces back as reflected ray.
TYPE OF REFLECTION
There are three of reflections. They are diffuse, mirror and retort reflection.
Diffuse reflection occurs when light strikes rough surface such as clothing and foliage. These surfaces cause the light to scatter in all direction. No reflection formed.
Mirror reflection occurs when light strikes surface that are smooth and glossy. The light reflects off the surface at an equal, but opposite angle to the source. Reflection is formed.
Retort reflection occurs when surfaces return a portion of directed light back to its source.
USES OF REFLECTION
For looking at yourself, making look bigger than it suppose to and checking of shoplifter etc.
I learn that there are more to learn from the internet than the textbook. The information the textbook is too limited.
Information from:http://www.tpub.com/neets/tm/106-3.htm
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