The 1st periodical test of physics is just hard!!!
Imagine that I spent all the time to study the formulas blah,blah,blah
FOCUSING ON PHYSICS IN 3...2....1...FOCUSED
AWWWWW
All the needed formulas are there!!!
wahahha
it just means this principle
When the teacher gives a test:
No review=review the things not mentioned
WAO!
Saturday, August 18, 2007
Thursday, August 2, 2007
Lenses and Optics
LENSES
A lens is a device that causes light to either converge and concentrate or to diverge. It is usually formed from a piece of shaped glass or plastic. Analogous devices used with other types of electromagnetic radiation are also called lenses: for instance, a microwave lens can be made from paraffin wax.
Lenses are classified by the curvature of the two optical surfaces. A lens is biconvex (also called double convex, or just convex) if both surfaces are convex, likewise, a lens with two concave surfaces is biconcave (or just concave). If one of the surfaces is flat, the lens is plano-convex or plano-concave depending on the curvature of the other surface. A lens with one convex and one concave side is convex-concave, and in this case if both curvatures are equal it is a meniscus lens. (Sometimes, meniscus lens can refer to any lens of the convex-concave type).
If the lens is biconvex or plano-convex, a collimated or parallel beam of light travelling parallel to the lens axis and passing through the lens will be converged (or focused) to a spot on the axis, at a certain distance behind the lens (known as the focal length). In this case, the lens is called a positive or converging lens.
If the lens is biconcave or plano-concave, a collimated beam of light passing through the lens is diverged (spread); the lens is thus called a negative or diverging lens. The beam after passing through the lens appears to be emanating from a particular point on the axis in front of the lens; the distance from this point to the lens is also known as the focal length, although it is negative with respect to the focal length of a converging lens.
If the lens is convex-concave (a meniscus lens), whether it is converging or diverging depends on the relative curvatures of the two surfaces. If the curvatures are equal, then the beam is neither converged nor diverged.
FIBER OPTICS
Fiber optics is the overlap of applied science and engineering concerned with such optical fibers. Optical fibers are widely used in fiber-optic communication, which permits transmission over longer distances and at higher data rates than other forms of wired and wireless communications. They are also used to form sensors, and in a variety of other applications.
The term optical fiber covers a range of different designs including graded-index optical fibers, step-index optical fibers, birefringent polarization-maintaining fibers and more recently photonic crystal fibers, with the design and the wavelength of the light propagating in the fiber dictating whether or not it will be multi-mode optical fiber or single-mode optical fiber. Because of the mechanical properties of the more common glass optical fibers, special methods of splicing fibers and of connecting them to other equipment are needed. Manufacture of optical fibers is based on partially melting a chemically doped preform and pulling the flowing material on a draw tower. Fibers are built into different kinds of cables depending on how they will be used.
MIRRORS
Convex mirror
A convex mirror diagram showing the focus, focal Length, centre of curvature, principal axis, etc
A convex mirror, or diverging mirror, is a curved mirror in which the reflective surface bulges toward the light source. Such mirrors always form a virtual image, since the focus F and the centre of curvature 2F are both imaginary points "inside" the mirror, which cannot be reached.
A collimated (parallel) beam of light diverges (spreads out) after reflection from a convex mirror, since the normal to the surface differs with each spot on the mirror.
Image
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". The passenger-side mirror on a car is typically a convex mirror. In some countries, these are labelled 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.
Concave mirrors
A concave mirror diagram showing the focus, focal Length, centre of curviture, principal axis, etc.
A concave mirror, or converging mirror, has a reflecting surface that bulges inward (away from the incident 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.
Image
This sculpture has both convex and concave reflective surfaces.
Note: S here stands for distance between object and mirror.
When S < F, the image is:
Virtual
Upright
Magnified (larger)
When S = F, 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 ∞.
When F < S < 2F, the image is:
Real
Inverted (vertically)
Magnified (larger)
When S = 2F, the image is:
Real
Inverted (vertically)
Same size
When S > 2F, the image is:
Real
Inverted (vertically)
Diminished (smaller)
A lens is a device that causes light to either converge and concentrate or to diverge. It is usually formed from a piece of shaped glass or plastic. Analogous devices used with other types of electromagnetic radiation are also called lenses: for instance, a microwave lens can be made from paraffin wax.
Lenses are classified by the curvature of the two optical surfaces. A lens is biconvex (also called double convex, or just convex) if both surfaces are convex, likewise, a lens with two concave surfaces is biconcave (or just concave). If one of the surfaces is flat, the lens is plano-convex or plano-concave depending on the curvature of the other surface. A lens with one convex and one concave side is convex-concave, and in this case if both curvatures are equal it is a meniscus lens. (Sometimes, meniscus lens can refer to any lens of the convex-concave type).
If the lens is biconvex or plano-convex, a collimated or parallel beam of light travelling parallel to the lens axis and passing through the lens will be converged (or focused) to a spot on the axis, at a certain distance behind the lens (known as the focal length). In this case, the lens is called a positive or converging lens.
If the lens is biconcave or plano-concave, a collimated beam of light passing through the lens is diverged (spread); the lens is thus called a negative or diverging lens. The beam after passing through the lens appears to be emanating from a particular point on the axis in front of the lens; the distance from this point to the lens is also known as the focal length, although it is negative with respect to the focal length of a converging lens.
If the lens is convex-concave (a meniscus lens), whether it is converging or diverging depends on the relative curvatures of the two surfaces. If the curvatures are equal, then the beam is neither converged nor diverged.
FIBER OPTICS
Fiber optics is the overlap of applied science and engineering concerned with such optical fibers. Optical fibers are widely used in fiber-optic communication, which permits transmission over longer distances and at higher data rates than other forms of wired and wireless communications. They are also used to form sensors, and in a variety of other applications.
The term optical fiber covers a range of different designs including graded-index optical fibers, step-index optical fibers, birefringent polarization-maintaining fibers and more recently photonic crystal fibers, with the design and the wavelength of the light propagating in the fiber dictating whether or not it will be multi-mode optical fiber or single-mode optical fiber. Because of the mechanical properties of the more common glass optical fibers, special methods of splicing fibers and of connecting them to other equipment are needed. Manufacture of optical fibers is based on partially melting a chemically doped preform and pulling the flowing material on a draw tower. Fibers are built into different kinds of cables depending on how they will be used.
MIRRORS
Convex mirror
A convex mirror diagram showing the focus, focal Length, centre of curvature, principal axis, etc
A convex mirror, or diverging mirror, is a curved mirror in which the reflective surface bulges toward the light source. Such mirrors always form a virtual image, since the focus F and the centre of curvature 2F are both imaginary points "inside" the mirror, which cannot be reached.
A collimated (parallel) beam of light diverges (spreads out) after reflection from a convex mirror, since the normal to the surface differs with each spot on the mirror.
Image
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". The passenger-side mirror on a car is typically a convex mirror. In some countries, these are labelled 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.
Concave mirrors
A concave mirror diagram showing the focus, focal Length, centre of curviture, principal axis, etc.
A concave mirror, or converging mirror, has a reflecting surface that bulges inward (away from the incident 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.
Image
This sculpture has both convex and concave reflective surfaces.
Note: S here stands for distance between object and mirror.
When S < F, the image is:
Virtual
Upright
Magnified (larger)
When S = F, 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 ∞.
When F < S < 2F, the image is:
Real
Inverted (vertically)
Magnified (larger)
When S = 2F, the image is:
Real
Inverted (vertically)
Same size
When S > 2F, the image is:
Real
Inverted (vertically)
Diminished (smaller)
Tuesday, July 17, 2007
**Nature of Light**
CORPUSCULAR THEORY
According to the corpuscular theory of light, set forward by Sir Isaac Newton, light is made up of small discrete particles called "corpuscles" (little particles). In its contemporary incarnation, the theory of Photons, this idea explains many properties of light, in particular the photoelectric effect. However, it fails to explain other effects, such as interference and diffraction. It was therefore superseded by the wave theory of light, later understood as part of electromagnetism, and eventually supplanted by modern quantum mechanics and the wave–particle duality.
WAVE THEORY
The Huygens–Fresnel principle (named for Dutch physicist Christiaan Huygens, and French physicist Augustin-Jean Fresnel) is a method of analysis applied to problems of wave propagation (both in the far field limit and in near field diffraction). It recognizes that each point of an advancing wave front is in fact the center of a fresh disturbance and the source of a new train of waves; and that the advancing wave as a whole may be regarded as the sum of all the secondary waves arising from points in the medium already traversed. This view of wave propagation helps better understand a variety of wave phenomena, such as diffraction.
Reflection
is the bouncing of light when it is "reflected" from a surface:
is the bending of light from one medium to another
Diffraction
Diffraction refers to various phenomena associated with wave propagation, such as the bending, spreading and interference of waves passing by an object or aperture that disrupts the wave. It occurs with any type of wave, including sound waves, water waves, electromagnetic waves such as visible light, x-rays and radio waves. Diffraction also occurs with matter – according to the principles of quantum mechanics, any physical object has wave-like properties. While diffraction always occurs, its effects are generally most noticeable for waves where the wavelength is on the order of the feature size of the diffracting objects or apertures.
Rectilinear Propagation
Rectilinear propagation is a wave property which states that waves propagate (move or spread out) in straight lines. This property applies to both transverse and longitudinal waves. Even though a wave front may be bent (the waves created by a rock hitting a pond) the individual waves are moving in straight lines.
Interference
As most commonly used, the term interference usually refers to the interaction of waves which are correlated or coherent with each other, either because they come from the same source or because they have the same or nearly the same frequency.
Einstein: light quanta
According to the corpuscular theory of light, set forward by Sir Isaac Newton, light is made up of small discrete particles called "corpuscles" (little particles). In its contemporary incarnation, the theory of Photons, this idea explains many properties of light, in particular the photoelectric effect. However, it fails to explain other effects, such as interference and diffraction. It was therefore superseded by the wave theory of light, later understood as part of electromagnetism, and eventually supplanted by modern quantum mechanics and the wave–particle duality.
WAVE THEORY
The Huygens–Fresnel principle (named for Dutch physicist Christiaan Huygens, and French physicist Augustin-Jean Fresnel) is a method of analysis applied to problems of wave propagation (both in the far field limit and in near field diffraction). It recognizes that each point of an advancing wave front is in fact the center of a fresh disturbance and the source of a new train of waves; and that the advancing wave as a whole may be regarded as the sum of all the secondary waves arising from points in the medium already traversed. This view of wave propagation helps better understand a variety of wave phenomena, such as diffraction.
For example, if two rooms are connected by an open doorway and a sound is produced in a remote corner of one of them, a person in the other room will hear the sound as if it originated at the doorway. As far as the second room is concerned, the vibrating air in the doorway is the source of the sound. The same is true of light passing the edge of an obstacle, but this is not as easily observed because of the short wavelength of visible light.
Huygens principle mathematically follows from the fundamental postulate of quantum electrodynamics – that wavefunctions of every object propagate over any and all allowed (unobstructed) paths from the source to the given point. It is then the result of interference (addition) of all path integrals that defines the amplitude and phase of the wavefunction of the object at this given point, and thus defines the probability of finding the object (say, a photon) at this point. Not only light quanta (photons), but electrons, neutrons, protons, atoms, molecules, and all other objects obey this simple principle.
PROPERTIES OF LIGHTReflection
is the bouncing of light when it is "reflected" from a surface:
- Specular when in a smooth surface
- Diffused reflection if in a rough surface
is the bending of light from one medium to another
Diffraction
Diffraction refers to various phenomena associated with wave propagation, such as the bending, spreading and interference of waves passing by an object or aperture that disrupts the wave. It occurs with any type of wave, including sound waves, water waves, electromagnetic waves such as visible light, x-rays and radio waves. Diffraction also occurs with matter – according to the principles of quantum mechanics, any physical object has wave-like properties. While diffraction always occurs, its effects are generally most noticeable for waves where the wavelength is on the order of the feature size of the diffracting objects or apertures.
Rectilinear Propagation
Rectilinear propagation is a wave property which states that waves propagate (move or spread out) in straight lines. This property applies to both transverse and longitudinal waves. Even though a wave front may be bent (the waves created by a rock hitting a pond) the individual waves are moving in straight lines.
Interference
As most commonly used, the term interference usually refers to the interaction of waves which are correlated or coherent with each other, either because they come from the same source or because they have the same or nearly the same frequency.
Einstein: light quanta
Albert Einstein's mathematical description in 1905 of how the photoelectric effect was caused by absorption of quanta of light (now called photons), was in the paper named "On a Heuristic Viewpoint Concerning the Production and Transformation of Light". This paper proposed the simple description of "light quanta," or photons, and showed how they explained such phenomena as the photoelectric effect. His simple explanation in terms of absorption of single quanta of light explained the features of the phenomenon and the characteristic frequency. Einstein's explanation of the photoelectric effect won him the Nobel Prize (in Physics) of 1921.
The idea of light quanta began with Max Planck's published law of black-body radiation ("On the Law of Distribution of Energy in the Normal Spectrum". Annalen der Physik 4 (1901)) by assuming that Hertzian oscillators could only exist at energies E proportional to the frequency f of the oscillator by E = hf, where h is Planck's constant. By assuming that light actually consisted of discrete energy packets, Einstein wrote an equation for the photoelectric effect that fit experiments (it explained why the energy of the photoelectrons was dependent only on the frequency of the incident light and not on its intensity: a low intensity, high frequency source could supply a few high energy photons, whereas a high intensity, low frequency source would supply no photons of sufficient individual energy to dislodge any electrons). This was an enormous theoretical leap but the reality of the light quanta was strongly resisted. The idea of light quanta contradicted the wave theory of light that followed naturally from James Clerk Maxwell's equations for electromagnetic behavior and more generally, the assumption of infinite divisibility of energy in physical systems. Even after experiments showed that Einstein's equations for the photoelectric effect were accurate resistance to the idea of photons continued, since it appeared to contradict Maxwell's equations, which were well understood and verified.
Einstein's work predicted that the energy of the ejected electrons increases linearly with the frequency of the light. Perhaps surprisingly, that had not yet been tested. In 1905 it was known that the energy of the photoelectrons increased with increasing frequency of incident light -- and independent of the intensity of the light. However, the manner of the increase was not experimentally determined to be linear until 1915 when Robert Andrews Millikan showed that Einstein was correct.[7]
Sunday, July 15, 2007
Long Test very hard >.<
the long test given by mr mendoza is very hard but of all that waaahhhhhhh ....
VIRUS amf >.< there is a virus at my PC from mr mendoza
I won an I phone click here www.thecoolpictures.com hahaha
cLiCk iT ReaLly GOOOD mmmmmmHHHHH
VIRUS amf >.< there is a virus at my PC from mr mendoza
I won an I phone click here www.thecoolpictures.com hahaha
cLiCk iT ReaLly GOOOD mmmmmmHHHHH
Saturday, June 30, 2007
Component And Graphical Method
Component Method
S=Sine
O=Opposite
H=Hypothenuse
•CAH•
C=Cosine
A=Adjacent
H=Hypothenuse
TOA
T=Tangent,O=Opposite,A=Adjacent
Graphical Method
- Get the datas you can use
- Determine the 90 degree triangle that you can use...
- If it is adjacent side use CAH
- If it is opposite side use SOH
S=Sine
O=Opposite
H=Hypothenuse
•CAH•
C=Cosine
A=Adjacent
H=Hypothenuse
TOA
T=Tangent,O=Opposite,A=Adjacent
Graphical Method
- Get the datas you can use
- Write a legend to determine the different vectors
- Plot the different vectors into a graph
- Measure the distance from the vector
Thursday, June 14, 2007
wakokok...
First test... what do you mean that just a quiz of two items is that hard for us to get zeroes...?
waaaaaaaaaa
I got mistakes because of units...?
this is the worst test scene I've ever seen ^__^
next time...
STUDY MORE SO THAT YOU WILL NOT GET ZERO...
ESPECIALLY AT THE 2 ITEM TESTS
till next time
First test... what do you mean that just a quiz of two items is that hard for us to get zeroes...?
waaaaaaaaaa
I got mistakes because of units...?
this is the worst test scene I've ever seen ^__^
next time...
STUDY MORE SO THAT YOU WILL NOT GET ZERO...
ESPECIALLY AT THE 2 ITEM TESTS
till next time
Thursday, June 7, 2007
1st time...!
hehehehe...
That was a very hard but exciting lesson we've learned from physics III...
I think that we really need to practice the lesson of sine, cosine and tangent so that we can apply it to our trigonometry class...
This way our trigonometry class and physics class together will make a smooth study...
very hard ei..=p
OUCH>>>?
Our assignment for today was very hard but we've managed to make some things in it...
See you next time...
That was a very hard but exciting lesson we've learned from physics III...
I think that we really need to practice the lesson of sine, cosine and tangent so that we can apply it to our trigonometry class...
This way our trigonometry class and physics class together will make a smooth study...
very hard ei..=p
OUCH>>>?
Our assignment for today was very hard but we've managed to make some things in it...
See you next time...
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