.}

.Wednesday, August 15, 2007 ' 3:56 AM Y

you used to be the reason, for my smile.

A technology that uses glass (or plastic) threads (fibers) to transmit data.

A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves.
Fiber optics has several advantages over traditional metal communications lines:
Fiber optic cables have a much greater bandwidth than metal cables. This means that they can carry more data.
Fiber optic cables are less susceptible than metal cables to interference.
Fiber optic cables are much thinner and lighter than metal wires.
Data can be transmitted digitally (the natural form for computer data) rather than analogically.

.Saturday, August 11, 2007 ' 3:47 AM Y

you used to be the reason, for my smile.

1.)Pick a point on the top of the object and draw two incident rays traveling towards the mirror.
Using a straight edge, accurately draw one ray so that it passes exactly through the focal point on the way to the mirror. Draw the second ray such that it travels exactly parallel to the principal axis. Place arrowheads upon the rays to indicate their direction of travel.

2.)Once these incident rays strike the mirror, reflect them according to the two rules of reflection for concave mirrors.
The ray that passes through the focal point on the way to the mirror will reflect and travel parallel to the principal axis. Use a straight edge to accurately draw its path. The ray which traveled parallel to the principal axis on the way to the mirror will reflect and travel through the focal point. Place arrowheads upon the rays to indicate their direction of travel. Extend the rays past their point of intersection.

3.)Mark the image of the top of the object.
The image point of the top of the object is the point where the two reflected rays intersect. If your were to draw a third pair of incident and reflected rays, then the third reflected ray would also pass through this point. This is merely the point where all light from the top of the object would intersect upon reflecting off the mirror. Of course, the rest of the object has an image as well and it can be found by applying the same three steps to another chosen point.

4.)Repeat the process for the bottom of the object.
The goal of a ray diagram is to determine the location, size, orientation, and type of image which is formed by the concave mirror. Typically, this requires determining where the image of the upper and lower extreme of the object is located and then tracing the entire image. After completing the first three steps, only the image location of the top extreme of the object has been found. Thus, the process must be repeated for the point on the bottom of the object. If the bottom of the object lies upon the principal axis (as it does in this example), then the image of this point will also lie upon the principal axis and be the same distance from the mirror as the image of the top of the object. At this point the entire image can be filled in.

source:http://www.glenbrook.k12.il.us/gbssci/phys/class/refln/u13l3d.html

.Friday, August 10, 2007 ' 4:56 AM Y

you used to be the reason, for my smile.

SIMILARITIES OF THE EYE AND THE CAMERA

1.opening for light to enter
Camera:aperture
Eye:pupil

2.control the amount of light entering camera/eye
Camera:diaphragm control size of aperture
Eye:iris muscles control size of pupil

3.refract light
Camera:glass biconvex lens
Eye:mainly cornea ; lens, aqueous & vitreous humor

4.object of light action to form image
Camera:photosensitive chemicals on film
Eye:photoreceptors(rods & cones) in retina

5.absorb excessive light to prevent multiple images formation
Camera:dark internal surface
Eye:pigmented, dark choroid

.Monday, July 30, 2007 ' 5:26 AM Y

you used to be the reason, for my smile.

desthis month we studied about lights and optics.

i've learned about different spherical mirror, the CONCAVE and the CONVEX MIRRORS.

i also learned how to do the ray diagram in mirror and the mirror equation which is

1/f=1/di+1/do

.Saturday, June 30, 2007 ' 4:29 AM Y

you used to be the reason, for my smile.

When both the x-component and the y-component are drawn, a right triangle is formed with the original vector being the hypotenuse:

This right triangle will allow us to to do right triangle trigonometry using SOH-CAH-TOA definitions. Those definitions are briefly explained here, and they are explained in much more depth in the Right Triangle Trigonometry section in the Trigonometry Realms of Zona Land.
Here are the right triangle definitions for the sine, cosine, and tangent of an acute angle in a right triangle:

Usually we just summarize these three definitions with these three short sentences:

The sine equals opposite over hypotenuse.

The cosine equals adjacent over hypotenuse.

The tangent equals opposite over adjacent.

Now, let's get back to our right triangle formed by the original vector and its x-component and y-component. Here's the diagram, fully labeled:

Notice that the x-component forms the side adjacent to the 35 degree angle, and that the y-component forms the opposite side to the 35 degree angle.

Let's find the size of the x-component; that is, let's find the size of the adjacent side.
We know the hypotenuse, (316 Newtons), and we know the angle, (35 degrees). We want to find the length of the adjacent side, (x-component). What trigonometry function relates the hypotenuse, an acute angle and its adjacent side in a right triangle? The cosine function does. The math looks this way:

Now, since the original vector is named F, its x-component is named Fx. This would be read 'F sub x'. So, in the above math we should remove 'x-component' and replace that term with Fx, as in:

We can solve for Fx by doing a little algebra and looking up the cosine of thirty-five degrees:

So, the x-component of the original vector is equal in size to 259 Newtons.

Now, realize this: The method for finding the x-component described here will not tell you the sign, (+ or -) for its value. This method will only tell you the size of the component. Notice that the x-component is pointing to the right. This makes it a positive x-component. (It would be negative if it pointed to the left.) So, we would would finally conclude that the x-component has a size of positive 259 Newtons.

Okay, now let's find the size of the y-component; that is, let's find the size of the opposite side. Again, we know the hypotenuse, (316 Newtons), and we know the angle, (35 degrees). We want to find the length of the opposite side, (y-component). It is the sine function that relates the hypotenuse, an acute angle and its opposite side in a right triangle. The math looks this way:

Now, since the original vector is named F, its y-component is named Fy which would be read 'sub y'. So, in the above math we should remove 'y-component' and replace that term with Fy, as in:

We can solve for Fy much like we solved for Fx:

.Thursday, June 28, 2007 ' 5:00 AM Y

you used to be the reason, for my smile.

The word components, in the following context, means parts. So, to talk about the components of a vector, we mean the parts of a vector.
For a great amount of situations the important parts of a vector are it's x-part and its y-part, or its x-component and its y-component. Here we will see how to find the x-component and the y-component of a vector.
The vector we will use in the following discussion is a force vector. The methods shown here, though, are true for any vector, such as a displacement, velocity, or acceleration vector.

If you drop a line from the tip of the original vector straight down to the x-axis and draw a vector along the x-axis from the origin to where this line hits the x-axis, then this newly drawn vector is the x-component of the original vector. In the diagram the line that was dropped down is shown as a thin black line and the x-component is shown as a red vector:

The tip of the x-component vector is directly below the tip of the original vector.

In the following diagram the thin black horizontal line marks how high up the original vector rises. A vertical vector, (parallel to the y-axis), which rises to this height is called the y-component of the original vector. The y-component is shown below in green:

.Monday, June 11, 2007 ' 2:00 AM Y

you used to be the reason, for my smile.

wLa namang nangyaRi..type Q Lang mg pOst..para maY Laman na unG bLog Q..
ansYa tLga ngaUng mOndAy kC wLang pAsOk...sNa mg impRove 2ng bLog Q..