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Physics Task about Light, Mirror, lenses and Optical Instrument
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Physics Task about Light, Mirror, lenses and Optical Instrument
LIGHT
Light is an electromagnet wave, namely the wave the vibration of which is electric field and magnetic field. Because the direction of vibration of the field and magnetic field are perpendicular to its spreading direction then light is included into TRANSVERSE WAVE
DEFINITION AND PROPERTIES OF LIGHT
1) Spreading According To Straight LineFor example : in dark room is made a
little slit so sunlight can enter. Sunlight that enters will be seen spreading according to straight line.
PROPERTIES OF LIGHT
2) Has EnergyLight has energy, such as sunlight which
is used to dry clothes. That shows light contains heat energy.
3) Can be SeenThe light radiates from light source,
such as sun, flash light, candle, and so on can be seen by our eyes.
4) Radiated in the Form of Radiationlight is an electromagnetic wave that is
radiated in the form of radiation. Radiation is energy emitted from a source in the form of rays or waves.
5) Has Spreading Direction Perpendicular to Vibration Direction
As wave, light is included into transverse wave, which is spreading direction is perpendicular to the direction of vibration.
6) Can Experience Reflection, Refraction, Interference, Diffraction, And Polarization
In everyday life, when the night comes we cannot see the things around us without the aid of the light, such as moonlight, or lamp. Means there are things that can radiate light their self and there are also things that cannot radiate light their self. Their bodies that can radiate light is called light source. Example: sun. The bodies that cannot radiate light their self is called dark body. Example: stone, wood, planets, and so on
Dark body if gets light can be separated into 3 kinds, namely:
1. Opaque body, namely a dark body that does not continue at all the light it receive. FOR EXAMPLE: carton, book, and wood.
2. Transparent body, namely dark body that continue a part of light it receive. FOR EXAMPLE: thin paper
3. Clear body, namely dark body that continue almost all light it receive. FOR EXAMPLE: clear glass.
DARK BODY
The image formed from a body is divided into two kinds, those are Umbra and Penumbra.
Umbra is the region that doesn't receive light at all so appears dark.
Penumbra is the region that receive a part of light so appears vague.
UMBRA AND PENUMBRA
LIGHT REFLECTION
Law of Light Reflection
r i
From the figure in the above, ray from the flash light in the box to mirror is called incident ray. Flat mirror has function as reflection plane and the ray reflected from the mirror is called reflected ray. Incident angle is the angle formed by incident ray and normal line. Reflected angle r is angle formed by reflected ray and normal line.
By the activity above is obtained the following conclusion:
a) Incident angle, normal line and reflected ray lie on one flat plane.
b) Incident angle is equal to reflected angle (i= r)
Reflection happens if the stream of light falls on the body that its surface is smooth and shiny, so direction of the light reflection goes to certain direction. In everyday life the specular reflection can be observed in light reflection by mirror and shiny metal surface.
The Kinds of Light Reflection
If the light falls on the rough surface (not flat), then the stream of light will be reflected to every direction irregularly.
This irregular light is called diffuse reflection. So, the diffuse reflection happens if the stream of light falls on the body which its surface is rough (not flat), so the stream of parallel rays which fall on the body will be reflected to every direction.
THE PICTURE
Specular reflection Diffuse reflection
A flat mirror is the glass the surface of which is flat and one of its surface is covered with silver metal. In every day life the mirror that we usually use to make up is the flat mirror
Light Reflection on Flat Mirror
Beside flat mirror there is also another mirror that can reflected light, namely concave mirror. Concave mirror is a mirror the surface of which is shiny and curves inward like slice of ball that is inner part is shiny.
Light Reflection in Concave Mirror
Light reflection in the concave mirror some have particular properties depend on the incoming of the light. There are three particular rays in the concave mirror.
a) Incident ray which is parallel to main axis of the mirror will be reflected passing through the focus point F.
b) The incident ray passing through the focus point F will reflected parallel to main axis.
c) The incident ray passing through center point of mirror C will be reflected back through that center point of curvature.
THE PICTURE
C F O
Figure a)
THE PICTURE
C F O
Figure b)
THE PICTURE
C F O
Figure c)
Convex mirror is inverse of concave mirror. In convex mirror the shiny surface lies is outer part of ball slice. So the surface that reflect light curves outward.
Light Reflection in Convex Mirror
Same with the concave mirror, the convex mirror also has particular rays, namely:
a) The Incident ray parallel to main axis is reflected seemed comes from focus point of the mirror (F).
b) Incident ray to focus point (F) is reflected parallel to main axis.
c) Incident ray to center of curvature of mirror C is reflected back seemed comes from the center point of curvature (on the same line).
THE PICTURE
O F C
Figure a)
THE PICTURE
O F C
Figure b)
THE PICTURE
O F C
Figure c)
Mirror
Mirror
A mirror is an object with at least one polished and therefore reflective surface. The most familiar type of mirror is the plane mirror, which has a flat surface. Curved mirrors are also used, to produce magnified or diminished images or focus light or simply distort the reflected image.
Mirror
Mirrors are commonly used for personal grooming (in which case the old-fashioned term "looking-glass" can be used), decoration, and architecture. Mirrors are also used in scientific apparatus such as telescopes and lasers, cameras, and industrial machinery. Most mirrors are designed for visible light; however, mirrors designed for other types of waves or other wavelengths of electromagnetic radiation are also used, especially in optical instruments.
Effect
In a plane mirror, a parallel beam of light changes its direction as a whole, while still remaining parallel; the images formed by a plane mirror are virtual images, of the same size as the original object (see mirror image). There are also concave mirrors, where a parallel beam of light becomes a convergent beam, whose rays intersect in the focus of the mirror. Lastly, there are convex mirrors, where a parallel beam becomes divergent, with the rays appearing to diverge from a common intersection "behind" the mirror.
Effect
Spherical concave and convex mirrors do not focus parallel rays to a single point due to spherical aberration. However, the ideal of focusing to a point is a commonly-used approximation. Parabolic reflectors resolve this, allowing incoming parallel rays (for example, light from a distant star) to be focused to a small spot; almost an ideal point. Parabolic reflectors are not suitable for imaging nearby objects because the light rays are not parallel.
Applications1. Safety and easier viewing: Rear-view mirrors are
widely used in and on vehicles (such as automobiles, or bicycles), to allow drivers to see other vehicles coming up behind them.
2. Two-way mirrors : A two-way mirror, also sometimes referred to as a one-way mirror or one-way glass, reflects some percentage of the light and lets some other percentage pass. It is a sheet of glass coated with a layer of metal only a few dozen atoms thick, allowing some of the light through the surface (from both sides). It is used between a dark room and a brightly lit room.
3. Signalling: With the sun as light source, a mirror can be used to signal by variations in the orientation of the mirror. The signal can be used over long distances, possibly up to 60 kilometres on a clear day.
Applications4. Televisions and projectors: Microscopic mirrors are a core element
of many of the largest high-definition televisions and video projectors. A common technology of this type is Texas Instruments' DLP. A DLP chip is a postage stamp-sized microchip whose surface is comprised of an array of millions of microscopic mirrors. The picture is created as the individual mirrors move to either reflect light toward the projection surface (pixel on), or toward a light absorbing surface (pixel off).
5. Instruments: Telescopes and other precision instruments use front silvered or first surface mirrors, where the reflecting surface is placed on the front (or first) surface of the glass (this eliminates reflection from glass surface ordinary back mirrors have).
6. Face-to-face mirrors: Two or more mirrors placed exactly face to face give the appearance of an infinite regress. Some devices use this to generate multiple reflections:
Fabry-Pérot interferometer Laser (which contains an optical cavity) some types of catoptric cistula momentum-enhanced solar sail
Applications7. Military applications: It has been said that
Archimedes used a large array of mirrors to burn Roman ships during an attack on Syracuse. This has never been proven or disproved; however, it has been put to the test. Recently, on a popular Discovery Channel show, MythBusters, a team from MIT tried to recreate the famous "Archimedes Death Ray“.
8. Seasonal lighting: Mirrors can be used to produce enhanced lighting effects in greenhouses or conservatories.
9. And many others
ApplicationsMirrors and animalsExperiments have shown that only large-brained social animals
are able to recognize that a mirror shows a reflection of themselves.
Animals that have shown they are able to use a mirror to study themselves:
Asian elephants Bonobos Common chimpanzees Dolphins Magpies Orangutans Lions Llamas Humans
Pictures
Asian Elephant Bonobo Common chimpanzee
Pictures
MagpieOrangutan
Dolphin
Pictures
HumansLlama
Lion
Unusual types of mirrorOther types of reflecting device are also called "mirrors". For example metallic
reflectors are used to reflect infrared light (such as in space heaters), or microwaves.
An acoustic mirror is a passive device used to reflect and perhaps to focus sound waves.
Active mirrors are mirrors that amplify the light they reflect. They are used to make disk lasers.
An atomic mirror is a device which reflects matter waves. Usually, atomic mirrors work at grazing incidence.
Cold mirrors are dielectric mirrors that reflect the entire visible light spectrum while efficiently transmitting infrared wavelengths.
Corner reflectors use three flat mirrors to reflect light back towards its source. They are used for emergency location, and even laser ranging to the Moon.
X-ray mirrors produce specular reflection of X-rays. All known types work only at angles near grazing incidence, and only a small fraction of the rays are reflected.
A non-reversing mirror is a mirror that provides a non-reversed image of its subject.
Curved MirrorA curved mirror is a mirror with a curved
reflective surface, which may be either convex (bulging outward) or concave (bulging inward). Most curved mirrors have surfaces that are shaped like part of a sphere, but other shapes are sometimes used in optical devices.
Convex Mirror A convex mirror, fish eye mirror or
diverging mirror, is a curved mirror in which the reflective surface bulges toward the light source. Convex mirrors reflect light outwards, therefore they are not used to focus light.
The image is always virtual (rays haven't actually passed though the image), diminished (smaller), and upright . These features make convex mirrors very useful: everything appears smaller in the mirror, so they cover a wider field of view than a normal plane mirror does as the image is "compressed".
Uses of Convex Mirror The passenger-side mirror on a car is typically a convex
mirror. In some countries, these are labeled with the safety warning "Objects in mirror are closer than they appear", to warn the driver of the convex mirror's distorting effects on distance perception.
Convex mirrors are used in some automated teller machines as a simple and handy security feature, allowing the users to see what is happening behind them. Similar devices are sold to be attached to ordinary computer monitors.
Camera phones use convex mirrors to allow the user correctly aim the camera while taking a self-portrait.
Properties of convex mirror can be found in objects not specifically designed for this purpose, such as some thumb tacks, Christmas baubles and even sunglasses.
Pictures of Convex Mirror
A convex mirror diagram showing the focus, focal Length, centre of curvature, principal axis, etc
Convex mirror image formation
Pictures of Convex Mirror
Convex mirror lets motorists see around a corner.
Concave MirrorA concave mirror, or converging mirror, has a
reflecting surface that bulges inward (away from the incident light). Concave mirrors reflect light inward to one focal point, therefore they are used to focus light. Unlike convex mirrors, concave mirrors show different types of image depending on the distance between the object and the mirror itself.
These mirrors are called "converging" because they tend to collect light that falls on them, refocusing parallel incoming rays toward a focus. This is because the light is reflected at different angles, since the normal to the surface differs with each spot on the mirror.
Plane Mirror
A plane mirror is a mirror with a planar reflective surface. For light rays striking a plane mirror, the angle of reflection equals the angle of incidence. Thus a collimated beam of light does not spread out after reflection from a plane mirror, except for diffraction effects.
Images A plane mirror makes images of objects in front of it; these images
appear to be behind the plane in which the mirror lies. A straight line drawn from part of an object to the corresponding part of its image makes a right angle with, and is bisected by, the surface of the plane mirror. The image formed by a plane mirror is always virtual (meaning that the light rays do not actually come from the image), upright, and of the same shape and size as the object it is reflecting.
Relation to curved mirrors Mathematically, a plane mirror can be considered to be the limit of
either a or a convex spherical curved mirror as the radius, and thus also the focal length, of the spherical mirror become extremely large.
Curved MirrorEffect on image of object's position relative to mirror focal point
Object's position (S),focal point (F)
Image Diagram
S < F(Object between focal point and mirror)
•Virtual•Upright•Magnified (larger)
S = F(Object at focal point)
•the image is formed at infinity.
(Note that the reflected light rays are parallel and do not meet the others. In this way, no image is formed or more properly the image is formed at infinity.)
Object's position (S),focal point (F)
Image Diagram
F < S < 2F(Object at 2x focal point)
•Real•Inverted (vertically)•Magnified (larger)
S = 2F•Real•Inverted (vertically)•Same size
Object's position (S),focal point (F)
Image Diagram
S > 2F•Real•Inverted (vertically)•Diminished (smaller)
Mirror Writing
Mirror writing is formed by writing in the direction that is the reverse of the natural way for a given language, such that the result is the mirror image of normal writing: it appears normal when it is reflected in a mirror.
Pictures
Eighteenth century mirror writing in Ottoman calligraphy. Depicts the
phrase 'Ali is the vicegerent of God' in both directions.
Pictures
Wikipedia in Leonardo's style.
Pictures
The notes on Leonardo da Vinci's famous Vitruvian Man image are in mirror writing.
Pictures
The notes on Leonardo da Vinci's famous Vitruvian Man image are in mirror writing.
Pictures of Mirror
A mirror, reflecting a vase.
Pictures of Mirror
Reflections in a spherical convex mirror. The photographer is seen at top right
Pictures of Mirror
A multi-facet mirror in the Kibble Palace conservatory, Glasgow, Scotland.
Pictures of Mirror
Triple mirror in a Irizar Eurorider bus
Pictures of Mirror
Glare from a following vehicle's headlamps in a rear view mirror
ALL ABOUT LENSES
Lens
Lens is transparent material that bordered with two bending planes
Lens will refract the light that come from object (Light behind object) and make virtual or real image of object
Types of Lens
There are two basic types of lens in the world (that I know), those are convex lens and concave lens
Convex lens has thinnest part in its side, while concave lens has thinnest part in its center
Part of Lens
Part of convex lens are:a) Focus point (Principal and virtual focus)
b) Principal axis
c) Lens Curvature
d) Optical Center
P1P2
Virtual Focus
Principal Axis
Optical Center
Ray
Principal Focus
Note! Virtual focus in convex lens is focus in coming ray side, usually added 2 (F2)
Convex Lens
There are 3 shape of convex lens.Biconvex
Plan-convex
Concave-convex Although there are 3 shape of convex lens,
the main system and characteristic is same
Properties of Convex LensA. Collect ray (Convergent)
B. Its focus has value (+)
C. Has two focus, virtual and principal focus
Particular Ray of Convex Lens
1. A ray parallel to principal axis is refracted through the principal focus
2. A ray through virtual focus is refracted parallel to principal axis
3. A ray through optical center is not refracted
See this picture
Example
P2 P1F2 F1
1.
P2 P1F2 F1
2.
P2 P1F2 F1
3.
The Image (Part 1)This is some examples of images that are formed by a convex lens
P1F2 F1
By using particular ray of convex lens, we can get...
Images beyond P2 ...(Room III)
P2
Real Image
The Image (Part 2)
P1F2 F1
If the object between P2 and F2 (Room II)... The images is...
P2
The Image (Part 4)
P1F2 F1
If the object between O and F2...(Room I)
P2
The images is virtual images...
Concave Lens
There is one again lens, concave lens Concave Lens has thinnest part in its center
Concave Lens
There are 3 shape of concave lens.Biconcave
Plan-concave
Convex-concave Although there are 3 shape of concave lens,
the main system and characteristic is same
Properties of Concave LensA. Spread ray (Divergent)
B. Its focus has value (-)
C. Has two focus, virtual and principal focus
Part of Lens
Part of concave lens are:a) Optical Center
b) Focus point (Principal and virtual focus)
c) Principal axis
d) Lens Curvature
Special Ray (Particular Ray)
1. A ray parallel to principal axis is refracted like from active focus point F1
2. A ray toward F2 is refracted parallel to principal axis
3. A ray through optical center is not refracted
Example
P2 P1F2 F1
1.
P2 P1F2 F1
2.
P2 P1F2 F1
3.
The Image This is some examples of images that are formed by a concave lens
By using particular ray of concave lens, we can get...
P2 P1F2 F1
The Image How if the object is located between F1 and P2?
Images that are formed is same! So, we get summary if concave lens always makes virtual, upright, and minimized image.
P2 P1F2 F1
Function of Lens
There are many function of lenses. With lens, we can make optical object, like magnifying glass, eyeglasses, microscope, and others
Count It!
In lens, there is also relationship between focus distance, object distance, and image distance. The formula is same with mirror
SiSof
111
f = Focus distance (m)
So = Object distance to lens (m)
Si = Image distance to lens (m)
Count It!
Beside focus, object distance, and image distance, we can calculate magnification and height of object and image.
o
i
o
i
S
S
h
hM
M = Magnification
ih = Height of image
oh = Height of object
So = Object distance to lens
Si = Image distance to lens
Power of Lens
There is also power of lens, beside magnification and focus. Power of lens more often used than the other. Example, you sometimes hear his glasses is -1, -2, -5. This is power of lens!
fP
1 = MagnificationP
f = Focus distance
Optic
OPTIC TOOLSOptics is the study of
the behaviour and properties of light including its interactions with matter and its detection by instruments. The word optics comes from ὀπτική, meaning appearance or look in ancient Greek.
Optics usually describes the behavior of visible, infrared, and ultraviolet light; however because light is an electromagnetic wave, similar phenomena occur in X-rays, microwaves, radio waves, and other forms of electromagnetic radiation and analogous phenomena occur with charged particle beams. Since the discovery by James Clerk Maxwell that light is electromagnetic radiation, optics has largely been regarded in theoretical physics as a sub-field of electromagnetism.
OPTIC NERVEThe optic nerve is
the second of twelve paired cranial nerves but is considered to be part of the central nervous system as it is derived from an out pouching of the diencephalons during embryonic development.
REFLECTION PRINCIPLEIn set theory, a branch
of mathematics, a reflection principle says that it is possible to find sets that resemble the class of all sets. There are several different forms of the reflection principle depending on exactly what is meant by "resemble".
REFLECTION FORMULA In mathematics, a reflection formula or reflection relation for
a function f is a relationship between f(a-x) and f(x). It is a special case of a functional equation, and it is very common in the literature to refer to use the term "functional equation" when "reflection formula" is meant.
Reflection formulas are useful for numerical computation of special functions. In effect, an approximation that has greater accuracy or only converges on one side of a reflection point (typically in the positive half of the complex plane) can be employed for all arguments.
The even and odd functions satisfy simple reflection relations around a=0. For all even functions,
Thank You For Your Nice Attention