October 21, 2010

Our hypothesis from yesterday was to answer why light bends. We realized that it bends because the light slows down. Another was our hypothesis from the homework from last night. It was asking how light will bend when it goes from less dense to more dense and more dense to less dense. In class today, we discovered the light will bend towards the normal line when it goes from more density to less density. When it is less to more, the light will slow down and it will bend towards the normal line.

In class, we also observed a container full of water, with playing cards taped to the sides. The bottom had a card, but from above looking down into the container you could see it. When you bend down and look from the side, it was not seen. The 3 of 4 sides had cards too. 2 sides had 2 cards, and 1 side only had 1. When you looked at 2 of the cards, you could only see 1/2 of it at some angles, but looking from the outside, the whole card was visible. You also couldn't see the cards from the outside, on the opposite side of the container.

After that observation was finished, we discovered the meaning of photon. Photon is the 2 ways that light can act. The first way is when light bounces off of a surface. This is called reflection. The other way, refraction, is when light bends. The Particle of Light is another meaning for reflection. It is like when we discovered the mirror experiment last week. The Wave Model of Light is also like refraction. This is the relation of when light slows down or speeds up.

We decided to make the Wave Model. So, we took a long, spring-like slinky and swung it, It looked like this (I could not find a good picture, but this is what was closest):

1 wave =

Refraction:

FAST: If light speeds up, it will look like this:

The wave legnths are closer together.

SLOW: If the light slows down, it will look like this:

The wave legnths are further apart.

Hypothesis of the day: Light moves through its speed and changes.

-A.L.

Period 2 Oct. 20

At the begining of class we talked about how we could walk through air, water, quick sand, and a 4 foot high wall. My group came up with this. For water we thought it would be harder because it is hard to put your foot in. Air it would be easy because we walk through it all the time. Quick sand would be very difficult because it is pulling you down. The wall we thought you could just climb over it since it is only 4 feet high. The class came up with as you go up it gets harder to go through, thenit becomes impossible. Then we talked about particles. We said it would look like a dot with one arrow. The arrow would be the direction and how fast the particle is going. We then drew how many particles would be in each. In the air there were little particles moving fast. Water there were more but moving slower. Quick sand there were also more but it was also moving slower. In the wall there were particles everywhere, and no movement. We can came up with the idea that the reason the water bent when we put water in it, the light literlly slows down. We then looked at a picture of light going into water. When the ray hit the water, some reflected, and some went in and bent. We siad that the bend in the light when it goes into water, it goes towards the normal line. Although when the light comes out of the water in bends away from the normal.
-MM

Mk Period 2 10/19/10

Today in class, we first got back our quiz corrections. Mr. Finley reminded us to look at the syllabus to see what should be included in them. Here is a link to the syllabus: http://www.npsd.k12.nj.us/20222069133223760/blank/browse.asp?A=383&BMDRN=2000&BCOB=0&C=60055

He said the biggest mistake was not including why you were mistaken. The next round of corrections is due a week from today, but Mr.Finley would rather you hand it in as early as possible.

Then Mr. Finley checked in our homework from the last two nights. (The questions on the video and the worksheets from yesterday) Then we went over the sheet. We decided that to correctly answer the question, we have to draw a straight line from the laser to the mirror. Then we measure the angle with our protractor and reproduce the same angle on the other side.

Below is a picture of the correct answers:

The back of the sheet was harder. We modeled it withe EC. She stood two feet away from the mirror. We called her Erin object. We called her reflection Erin Image. We established that because Erin object stood two feet from the mirror, Erin image looks like it is two feet from the mirror. In order to hit Erin object with the mirror, you have to be able to see Erin image. The same thing applies for the guy on our sheet. If Kenny object is where he is in the picture, then Kenny image is the same distance from the mirror. Eric has to be able to see Kenny image in order to hit Kenny. They increased in difficulty.

The correct answers are below

Then we went over two nights ago homework. We watched the video again.

We tried to figure out why it took the path it did. We realized that the rays on either side of the block are parallel. The reason some reflect is in JL's words escaping, is that it is reflecting off a little bit. It is going at the same angle. Some light passes through the block too. The only surprise, the direction changes. When it exited the the block, it went back up in the same amount it came down by.

Our bouncy ball model does not work for this case. The ball would bounce right back up, but the video shows the light go through and bend. A bullet might bend upward though because the water could be pushing it up. But in the video, the light went down

The whole video I thought was pretty confusing. Why does it bend? Why does some light reflect, but not all of it? The other sheets I thought were pretty straightforward. The best advice I could give you is to make sure you would be able to see the image in the mirror in order to hit the object. This will ensure you are accurately aiming. Also remember to draw straight lines, or the angles will be off. Finally remember to use a protractor, don't just eyeball it. Some answers are really close and you don't want to get a question wrong solely based on you forgetting to be accurate.

Mk

10/18/10

Today we had a sub. We started off with attendance. Then we read an article about light and did a work sheet. I'll probably blog again tomorrow.

-Yam

Period 2 October 15, 2010 JB

We changed seats so ask Finley where you sit if you were absent. We taked about analogies. An analogie is comparing things. We found analogies of light bouncing off a mirror. The laser is like a rain drop bounceing off a window, a bullet ricochaing off medal, and a bouncy ball bouncing off the floor. The bouncy ball hits the ground and bounces at the same angle. Another example is a basket ball hitting a backboard. In all of these examples the object goes at one angle, and hits something then, it goes off in the same angle on the other side. These are analogies, real life examples.



The simalarities of these situations are; that they are bouncing at the same angle, the surface changes, and the sources are different.



Some differences are; that they are at a different magnitued, the objects are aventually going to stop going straight and start heading down, they have different speeds, you can see the ball and not the light, they don't always travle in a straight line, and the bounce ball is solid matter, and the light is energy.



When using analogies you need to make sure it fits. For example, you can't use the bounce ball for explaning why we can see the light. A good analogy is a water balloon and how it hits the wall and explodes in every directing. Now were doing an experimeant that involes shinning a light into a beacher with water. We have found out that the laser, when shone through water, gets weaker.


We had a discussion in class on if a laser goes straight through when shone through water, or if it changes paths and bends when shone through water. We had HW to see if lights path changes direction. We have to watch a video and see if our bouncy ball model can explain whats happening.

JB

MA Period 2

Today in Period 2 Science we:
1. Talked about the scattering of light, otherwise known as why we don't see a concentreted reflected ray on some surfaces. The "some surfaces" in class was the wall. The wall was very rough, so we thought that the reason there is no concentrated ray because it was too rough. We also tested this on the mirror and whiteboard, confirming the fact that smooth and polished surfaces reflect a concentrated ray. We also used pond as an example; you can see your reflection in a pond when it is calm, then, when you throw a rock into it (making the surface rough, in a way), you can't see your reflection anymore.
2. However, when you point a laser at a window, which is smooth, it doesn't reflect off. So, we tested different surfaces with the laser to see which different surfaces reflect the laser.
Here's what we tested:
Window: not really, goes through
Wall: doesn't reflect
Glass test tube: not really, kinda goes through it
Plastic test tube: not really, just kinda goes through it
Person's jacket: no
An arm: no
Table: a little bit
Glossy poster: reflects off pretty well
Paper: sort of reflects and scatters at the same time

So, the light and the reflection is affected by the texture of the surface.
It is also affected by the color; for example: the black table, even though it was kinda shiny and flat, only reflected a little bit because the black color is absorbing some of the light.

There is a term for the idea that light can go straight through some surfaces; and that is transparency. This means that light can freely pass through it. An example of this is a glass beaker.
However, there is another term; it is translucent. This means that some light can pass through, but some also light also clearly reflects/absorbs some. An example of this is a window.
Opaque means that the object is solid, such as a shirt or something solid.

MA

Period 2 On 10-13-10 By MA

Hey people!!

So, today we had a sub, so we didn't do much.
But, we did:

1. Took a pop quiz on light
2. Had a word search to do

Ando no HW!

By the way,

Fin said he'd probably push the blogging schedule back a day,

so i'll blog again tomorrow.

MA Period 2