physics

the casual typical exagurational subject..

Monday, August 20, 2007

cotinuation of the previous post::::!!!himan eye vs camera

in a simple camera we can denoted that it has a negative magnification because it cannot produce a real image of the object.....

^___^
Due to the optical properties of photographic lenses, only objects within a certain range of distances from the camera will be reproduced clearly. The process of adjusting this range is known as changing the camera's focus. There are various ways of focusing a camera accurately. The simplest cameras have fixed focus and use a small aperture and wide-angle lens to ensure that everything within a certain range of distance from the lens, usually around 3 metres (10 ft) to infinity, is in reasonable focus. Fixed focus cameras are usually inexpensive types, such as single-use cameras. The camera can also have a limited focusing range or scale-focus that is indicated on the camera body. The user will guess or calculate the distance to the subject and adjust the focus accordingly. On some cameras this is indicated by symbols (head-and-shoulders; two people standing upright; one tree; mountains).
^___^
(wikipedia.com)

.....so the human eye andthe camera are the same in case of focus and magnification......

Wednesday, August 15, 2007

the difference between human eye and a camera

the human eye:

Eyes are organs of vision that detect light.
Different kinds of light-sensitive organs are found in a variety of organisms.
The simplest eyes do nothing but detect whether the surroundings are light or dark, while more complex eyes can distinguish shapes and colors. The visual fields of some such complex eyes largely overlap, to allow better depth perception (binocular vision), as in humans; and others are placed so as to minimize the overlap, such as in rabbits and chameleons.


All of the individual components through which light travels within the eye before reaching the retina are transparent, minimising dimming of the light. Light enters the eye from an external medium such as air or water, passes through the cornea, and into the first of two humours, the aqueous humour. Most of the light refraction occurs at the cornea which has a fixed curvature. The first humour is a clear mass which connects the cornea with the lens of the eye, helps maintain the convex shape of the cornea (necessary to the convergence of light at the lens) and provides the corneal endothelium with nutrients.

(wikipedia.com)

as it stated the human eye has a lens where the ligth is entering trough a focus
using a converging lens because the human eye has a lens which is converging

Sunday, August 5, 2007

xXxfiBerOpTiCxXx

i don`t no wat it is so i just based my answers on my resources.....

Fiber optics

•(optical fibers) are long, thin strands of very pure glass about the diameter of a human hair. They are arranged in bundles called optical cables and used to transmit light signals over long distances.


Parts of a single optical fiber

If you look closely at a single optical fiber, you will see that it has the following parts:

  • Core - Thin glass center of the fiber where the light travels
  • Cladding - Outer optical material surrounding the core that reflects the light back into the core
  • Buffer coating - Plastic coating that protects the fiber from damage and moisture
Hundreds or thousands of these optical fibers are arranged in bundles in optical cables. The bundles are protected by the cable's outer covering, called a jacket.

Optical fibers come in two types:

  • Single-mode fibers
  • Multi-mode fibers

Single-mode fibers have small cores (about 3.5 x 10-4 inches or 9 microns in diameter) and transmit infrared laser light (wavelength = 1,300 to 1,550 nanometers). Multi-mode fibers have larger cores (about 2.5 x 10-3 inches or 62.5 microns in diameter) and transmit infrared light (wavelength = 850 to 1,300 nm) from light-emitting-diodes (LEDs).

Some optical fibers can be made from plastic. These fibers have a large core (0.04 inches or 1 mm diameter) and transmit visible red light (wavelength = 650 nm) from LEDs.

How Does an Optical

Fiber Transmit Light?

Suppose you want to shine a flashlight beam down a long, straight hallway. Just point the beam straight down the hallway -- light travels in straight lines, so it is no problem. What if the hallway has a bend in it? You could place a mirror at the bend to reflect the light beam around the corner. What if the hallway is very winding with multiple bends? You might line the walls with mirrors and angle the beam so that it bounces from side-to-side all along the hallway. This is exactly what happens in an optical fiber.


Diagram of total internal reflection in an optical fiber

...expectations???...

anu b IbiG saBiHiN n2?

paNu? b gaGawIn 2?

weLL Ang alAm ko Lng ay
masaya daw ang physics
madami daw matututunan
at di TamaD ang TeaChEr

anG sAbI nGa eh dapat
EngliSh ung lanGuaGe na gagamitin!!

idon`T caRe
break the rules to be free!!

Saturday, August 4, 2007

mirror

everyday we uses mirror in different activities
but most of us don`t know what realiz is it

i`m here to explain it

mirror have its two kind
concave and convex

concave
>may produce a real or virtual image
>has a positive magnification
>object was facing the front of the mirror
>the image is erect

convex
>always produce virtual image
>has a negative magnification
>object is place behind the mirror

the nature of light

di ko maalala kung kailan pinagawa ni sir 2

ang alam ko lang nagkandabuholbuhol ako d2

pero e2 ung mga naintindihan ko

nature of light
>was defined in two aspects, the corpuscular theory and the wave theory.

>>the corpuscular theory states that light was made of tiny particles called corpuscular that has no mass.
>>newton`s law explains the reflecton and refraction of light

>>the wave theory explains taht light travels on wave motion because it arise from vacuum, like mostly in star cases, light travel on vacuum to reach the earth
>>huygen`s theory explains the diffusion and interference of light

>some in late 19th century, albert einstein conncluded that light was photosensitive materials.
>he decided that light was quantize and become the basis of quantum theory

o yan kahit konti may maiintindihan kau!!!

Friday, June 15, 2007

sir e2 na Yung PianpagAwa Nyu!!!!

I this example we will be adding the two vectors shown below using the component method. The vectors we will be adding are displacement vectors, but the method is the same with any other type of vectors, such as velocity, acceleration, or force vectors.

Let's take this all one step at a time. First, let's visualize the x-component and the y-component of d1. Here is that diagram showing the x-component in red and the y-component in green:The two components along with the original vector form a right triangle. Therefore, we can use right triangle trigonometry to find the lengths of the two components. That is, we can use the 'SOH-CAH-TOA' type of definitions for the sine, cosine, and tangent trigonometry functions.Let's find the x-component of d1. Notice that the x-component is adjacent to the angle of 34 degrees, so, we will use the cosine function since it relates an acute angle, the adjacent side to that angle, and the hypotenuse of a right triangle:

Now, using trigonometry like this will not tell us the sign, (+ or -), of this component, (or any other). So, we must check the diagram for positive or negative directions. This x-component is aimed to the right, so, it is positive:(Again, remember that these calculations presented here have decimals that have been truncated. Presenting calculations to many more decimals does not help clarify methods, and, also, it violates several rules of significant digits. In other words, these calculations are approximate. The calculator below keeps many more decimal places, so, its outputs will differ slightly.)

Now, let's find the y-component of d1. Notice that the y-component is opposite to the angle of 34 degrees, so, we will use the sine function since it relates an acute angle, the opposite side to that angle, and the hypotenuse of a right triangle:Again, check the diagram for positive or negative directions. The y-component aims up, so, it is positive:
Here is the diagram now showing the values for the x-component and y-component of d1:Next, let's see the x-component and the y-component of d2. Here is that diagram showing the x-component in red and the y-component in green:

We will now find the x-component of d2. Here the x-component is opposite the angle of 64 degrees, so we will use the sine function to find it:Check the diagram for positive or negative directions. This x-component points to the left, so, it is negative:And for our last component we will find the y-component of d2. The x-component is adjacent to the angle of 64 degrees in this diagram, so we will use the cosine function to find it:Check the diagram for positive or negative directions. This y-component is aimed up, so, it is positive:

Here is the diagram showing our newly calculated values for the components of d2:Now, we must add up like components to get the components for the total displacement.To get the total x-displacement, add up all of the separate x-components:To get the total y-displacement, add up all of the separate y-components:So, when these two vectors, d1 and d2, are added, the total, or sum, has an x-component of 9.2 meters and a y-component of 30.1 meters.To get the actual 2-D total displacement, add the total x-displacement and the total y-displacement. Here is a diagram with the total x-component shown in red and the total y-component shown in green and the 2_D total shown in blue:Use the Pythagorean theorem to get the magnitude (size) of the total 2-D displacement:Use the arctangent function to get the angle:Check the diagram for NSEW notation:Therefore, our final result for the total 2-D displacement can be stated as:Here's a diagram that shows this result:Again, the component method of addition can be summarized this way:Using trigonometry, find the x-component and the y-component for each vector. Refer to a diagram of each vector to correctly reason the sign, (+ or -), for each component. Add up both x-components, (one from each vector), to get the x-component of the total. Add up both y-components, (one from each vector), to get the y-component of the total. Add the x-component of the total to the y-component of the total then use the Pythagorean theorem and trigonometry to get the size and direction of the total.

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