We had a sub. We had a pop quiz. Ask Mr. Finley for it. That is all!

October 12, 2010 Lasers and Reflections (Period 1)

Today we started with more trials of our experiment of seeing if lasers reflect off of the mirror at the same angle as they were shot. We needed to make a prediction on what would happen when the laser was shot through the protractor onto to the mirror and see where it reflected. Hleb, Thomas, and I came up with the prediction that the laser should reflect off of the mirror at the same angle as the laser was shot. After doing 8 trials with the mirror and protactor we determined that when the laser is shot through the protractor it reflected off the mirror at the same angle that they were shot at. When shot at 10 degrees, the laser was reflected at 10 degrees. When the laser was shot at 20 degrees. it reflected at 20 degrees and so on. These experiments lead to the confirmation of our hypothesis that lasers reflect off of a mirror at the same angle as they were shot.

(A picture of what I saw when I shot the laser through the protractor onto the mirror)



Later, Finley talked to us about a couple of things on our lab reports. Remember that there are no claculations necessary for today's lab. Then we talked about uncertainty, which is one half of the smallest increment, something else to think about for taday's lab report.

We walked out of class today with a proven hypothesis of lasers reflect off of a mirror at the same angle as they are shot and some things to consider for our lab reports tonight with uncertainty and no calculations.

KS

October 11, 2010 - Playing with Lasers and Mirrors [ Period 1 ]

Today, we first started off by taking attendence. Then, we got started on the experiment. Our main question: "When a laser hits off the mirror, is angle A and B equivilent? We began to find out. Students experimented with a laser and mirror (most of which, were using a protractor too.) to see what happens when a laser bounces off a mirror/protracter, and to test their hypothesis. Of course the protractor was clear. I noticed a group of people were testing with the fish tank It appears as if when they put the mirror behind the fish tank, and point the laser to it, the laser kind of goes into an angle. If I draw a picture, you might have a better understanding of what I am talking about. It is what I saw.


People, though, were playing and being somewhat foolish with lasers and pointing them to the wall and ceiling. Now this may be off topic, but, when the laser hit the ceiling light, the light spread out. As in, the one point would show, but then a glow of light would with a clearer red (kind of like transparency, you could still see the ceiling light) than the one point. This only went for when the lights were turn off. Our subsitute said we should do at least three trials, which most groups did, and we gave a little time for the people who didn't do three trials. When we turned the lights on, people began to write up what they saw, and gave back all the lasers and mirrors.


Tables discussed their hypothesis together, which caused some heated discussions at some tables. Afterwards, we discussed as a whole class if the statement was true, that laser A and B were notequivilent. A couple of groups thought no, they are not equivilent. At the end, groups wrote up their conculsions in their own opinion, but help from their groups.


Fun fact: Did you know that the laser was invented in New Providence? I bet you didn't. Our morning substitute was just so awesome to let us on this fun fact.


CP

Lasers and Mirrors -Period 1

Today in class we discussed our homework which was how an image would look in the back of your eye. We drew a ray diagram and we saw that all rays cross right as they go into the pupil, which was just like our cardboard experiment. The light rays, instead of crossing at the whole in the cardboard, cross at the pupil. The other part of our homework was how does your brain process the image and we learned that in the brain, the image gets flipped so that we see it right side up.

We also discussed why different colors affect the laser. We cam to the conclusion that some colors absorb more light and some colors reflect more. But then we had an idea. What does the light look like on different surfaces? So we got a mirror to see what would happen with the laser on it. My group saw that you can see the light in the mirror but you could also see it on some other object just as clearly because the light is reflected off of the mirror. Conor also had a good idea. His idea was that i you point the laser at a 35 degree angle onto the mirror, it will reflect off at a 35 degree angle so that the two angle would be congruent. The Finley told us that even though our hypothesis worked with a flat mirror, will it work with a curved mirror? Finley had another question for us which was does the laser hit more that one point on the mirror? Yolanda had a good idea that if we hit the laser at any point on the curved mirror, that it would work just like a flat mirror and reflect the laser off at the same angle just like a flat mirror. We all eventually agreed on that and Finley also told us that the laser only hits one place on the mirror. After that Finley gave us a new vocabulary word, normal. He said that the normal is perpendicular to the line that the laser is reflecting off of. So our conclusion for the class was that light bounces off of a mirror at the same angle that you pointed the laser, no matter if the mirror is flat or curved.

KM

Period 1

Today in class we light up a candle and put it next to the wall, we drew a ray diagram of where the light was going to go. We drew the rays of where the rays from the candle were going. We wrote on the board that the light went from the candle and went everywhere and it bounced off the wall and towards us. This happend because there was light shining off the wall from the candle that we could see.

Next we had the light and a piece of cardboard, there was a hole in the piece of cardboard. When the candle was shining there was a dot on the wall from the candle through the cardboard. The dot was the image of the candle uside down. We drew up how this happend with the rays from the light. Every table in the class had a different idea of how the candle was upside down when it went through the little hole through the cardboard. We said that the light from the bottom went through the hole and went to the top of the shadow on the wall.

Absorbing Lasers and Experiment Assumptions -Period 1

Today, we pointed lasers at different materials to for different in the way it reflects and if there is a difference, then why. We found out that the walls and floors "cling more too light, and meetal and laminated paper, reflected it more. We then also figured out that the color of the laser piont colored different when it was on a black background and on a white background. We then decided thatthe black absorbed the light. Then we still had to figure out what happened when the laser got pointed on the wall. We decided to come back on that later.

Then Mr. Finley told us that our experiment on Friday had gave data that he had never seen before. We then tried to figure out his assumption that he made.

We made three guesses:

• The size of the light bulb
• We all had the lights on at the same time
• The type of the light bulb

The type of the light bulb did affect the experiment. When we did the experiment again with a normal light bulb the light did spread out everywhere, and ther was no circle on the ceiling. When we used the flood light there was a circle on the ceiling. This makes sense because a flood light is made to send all the light out in one direction.

We then went over the homework. We started by drawing our idea. Ryan went up and drew his idea. His drawing showed the light bulb with a few rays coming out. We then a

sked ourselves what was wrong with Ryan's drawing, if there was anything wrong. We decided that, yes, there was something wrong . There should be an infinite amount of rays coming out of one spot on the light bulb, and an infinite amount of rays coming out of the ligh

t bulb.Then Mr Finley, and the class changed it to the light bulb having an infinite amounts of rays coming out it, and an infinite amount of rays coming out every spot on the light bulb.

We then reminded ourselves

what we did on Friday, which was we tried to find out how many rays came out of one spot on the light bulb. Mr. Finley

also pointed out that if we drew curved lines on our quiz in the near future we would lose points, because we have tested this and know that they are straight. Then we asked ourselves what is happening when we move the cardboard closer to the wa

ll. We decided it became more concentrated. Why is it

more concentrated? Because there is less space for it .

We also got our quizzes back today. We were told that we have to work on our scientific writing a bit more. There are different kinds of letters on your quiz, next to your answers. These correspond with the rubric you can find online under the tab Course Information on Mr Finley's teacher webpage.

DB

Period 1 - Light

For homework last night, we had to design an experiment including a lightbulb, a socket, an exacto knife, a piece of cardboard, and a wall. The three hypotheses we came up with in class were, one ray fans out, the light will spread out everywhere, and it varies for the various bulb strengths. My group decided to test the second hypothesis. We put the light bulb into the socket, and cut a hole in the cardboard with the knife. We turned the light on and put the carboard over it. The results were that the light fanned out. The hypthesis was proved.





During the class discussion, we talked about the results of our experiments. On the white board, Mr. Finley drew how the light fans out through the hole in the carboard. The main points of the discussion were that the the light on the wall is bigger than the hole in the cardboard. The other point that we discussed is that if there were no sides of the cardboard the light will go in all directions. The light will go all of the directions it can reach. Also, light on the wall as the surface gets farther away.

I found this link that explained the concept a little more: http://www.accessexcellence.org/AE/AEC/CC/vision_background.php

TR