Thursday, August 16, 2007
CONVERGING LENSES--RAY DIAGRAM
The method of drawing ray diagrams for double convex lens is described below. The description is applied to the task of drawing a ray diagram for an object located beyond the 2F point of a double convex lens.
1.) Pick a point on the top of the object and draw three incident rays traveling towards the lens.
Using a straight edge, accurately draw one ray so that it passes exactly through the focal point on the way to the lens. 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. Draw the third incident ray such that it travels directly to the exact center of the lens.
2.) Once these incident rays strike the lens, refract them according to the three rules of refraction for converging lenses.
The ray that passes through the focal point on the way to the lens will refract 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 lens will refract and travel through the focal point. And the ray which traveled to the exact center of the lens will continue in the same direction. 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 refracted rays intersect. All three rays should intersect at exactly the same point. This point is merely the point where all light from the top of the object would intersect upon refracting through the lens. 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 double convex lens. 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, 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/refrn/u14l5da.html
trishaleen
6:16 AM
Tuesday, August 14, 2007
Update from the last post...I mentioned there that I got 21 for my partial point in the long test, now the final score 22.5! Such a great improvement huh? LOL.
The real reason for this post are 1.)Second Long Test 2.) Periodic Test 3.) And this blog as a whole.
SECOND LONG TEST
>>The second long test is a LITTLE bit easier, for me. At least I got 50% of the HPS. Another thing is I got +3. YEY!...Almost everyone got additional points too. No matter how small the additional point is, it will help a LOT because in Physics, EVERY POINT COUNTS. Haha.
PERIODIC TEST
>>The test was really hard. Although some of the questions given were somewhat similar from the past quizzes. As of now, that's all that I can say for the PT.
BLOG
>>I'm having a hard time editing this blog but I'm not complaining. It's just that, I am not familiar yet with blogging 'coz I am not really fond of making this online journal or whatsoever. Another is, I still don't have the post for vectors and ray diagram. I'm planning to have all of those stuff in this blog by Saturday (evening). Promise...promise...promise.
That's all for today. Promise, on Saturday.
trishaleen
5:02 AM
Friday, July 13, 2007
Long test was finally over. It was hard, for me. I am still confused with transformation of formulas. I am already workin' on it. I think I'm almost there but still has confusion. I dunno. I think I just have to ask a friend to teach me how. Just like what I did when I was confused with vectors. But now I'm already over with vectors and now I should focus on trans. of formula.
By the way, I already knew my partial score. 21 out of 70 items. How was that? I wish I would still have aditional points from the second chance that Mr. Mendoza gave us.
Now what? I have to think and come up with a nice way on how to tell my parents that....arrrg.. I know you get what I mean. Whoever you are reading my blog. Oh well, that's life. *tears* haha. Just kidding.
I have to go. I have to think of a way on how to understand physics better than ever.
trishaleen
6:27 AM
Friday, July 6, 2007
Waaaaaaaaaahhhhhhhhhh..........
We will have our LONG TEST on MONDAY!!!!
Shocks! I have to STUDY, STUDY, STUDY. I hope something will get into my mind. I wish that my brain would be able to absorb formulas and concepts I'll be needing to pass the test.
Arrggghhhh.
GOODLUCK.
trishaleen
5:57 AM
Sunday, July 1, 2007
Almost everyday we have a quiz. That's why I always have to listen to Sir Mendoza.
My score varies every quiz. On the first day I'll get half the HPS, the next day 0 (yes!) haha, on the other day 1 point. But I think that there was a time when I got a perfect score. Yey!
On our last activity about the waves was easy. I got 25/25. If only all the quizzes will be like that activity...
By the way, we willl be having a long test...maybe next week. Goodluck. I still have to work on transformation of formulas.
Oh well, that's life.
I'll be posting again soon.
trishaleen
1:11 AM
Monday, June 18, 2007
Wanna know the latest in our Physics class?!
Well, Mr. Mendoza discussed a new lesson. It was a brief history of light. Right after he discussed the topic, he gave us a quiz. Yes! Quiz again. That quiz proved that I hate math and I do have a hard time dealing with numbers and computations. Why?
Unlike the first two quizzes, our third quiz focused on the history of light. The quiz deals with terms and concepts taught to us. And because there were no computations at all, I got 8 out of 10. I hate myself for that. Hehe. (Joke!). I got two mistakes because I forgot the word "Specular". And so I wrote the wrong word. Arrggghhhh. But my score is not that bad right?!
Better luck next time. I hope there will be no computations again in our Physics class. Haha. Super impossible. Never mind. I will study (na lang).
trishaleen
5:20 AM
Sunday, June 17, 2007
Last week we had an All or Nothing Quiz. I called it all or nothing quiz because it was composed of two questions, five points each. There was no consideration for the effort we've exerted to answer the problem therefore no one got a point. Yey! I'm not alone.
Next day, we were given a make up quiz. Again, the quiz was composed of two problem. Thinking that the scoring system was the same with the all or nothing quiz, I didn't bother to expect any score. Surprisingly, Mr. Mendoza gave consideration for the effort this time. There was an amazing increase on my score from 0 to 3. Yes! At least I gained 3 point though it was still very very low.
Now I have made up my mind. I have to spend a lot of time studying Physics. *Waahh..I'm already starting to have a headache.* Haha. Just kidding. But really, I have to do something before I gain a lot of zeros in my quizzes...
I'll be posting again soon. Buhbye.
trishaleen
1:49 AM
Monday, June 11, 2007
I hate MATH..That's a fact. And every subject that include computations is difficult for me. PHYSICS include computations. So what does that mean?!
I just want to say that for me, PHYSICS is a HARD subject because it has computations but since its a part of MaSci's curriculum, I have to learn its concepts from basic to the most complex part. I know it will never be easy to get high grades in Physics because our teacher will be requiring us to pass these and that from time to time. I believe that all the hardships I will be encountering this school year is part of learning so for now, all I can do is to go with the flow, study hard and do all my best to understand the subject. GOODLUCK.
That's all for now. Until my next post. Buhbye.
trishaleen
2:31 AM