Period 1 10/20/10 Blog!!

Today in class...

First, we took attendance.


Next, Finley checked the homework. Our homework was to re-watch the video we saw in class. In the video, there is a laser. A block filled with water and nothing else is held up to the laser. When the laser hits the side of the block, the line no longer remains straight. Instead, the ray bends. Here is a link to the video: http://paer.rutgers.edu/pt3/movies/refraction.mov



We had to look for and discuss patterns:


Observations we made about the video-

• when the light hit the block it was no longer straight


• a faint ray was following the law of reflection and bounced off the block side


• some thought the light should not bend, but go straight

Did this activity follow the bouncy ball model (when the light hits an object, it bounces off at the same angle that it was shown) ? Why or why not? Why is the light doing this?

The light could slow down.

To figure this out, a student ran at Fin. When he approached Fin, he slowed down and tried to avoid him. When the collided, Fin pushed the student back.

Another example we used was if there was a bouncy ball launcher aimed at the water, and the water is pushing up, the ball would bounce back up and change paths. Although it should get pushed up, bounce off the water at equal angles (which it does a little bit), completely stop, go straight down in an unchanged path, or go down but get pushed up slightly, the ball actually got pushed down and rose back up.

The bending of the light inside the water and outside of the water are the same because it goes down and back up at the same angle. Why might this be happening?

Maybe water bends light because there could be some particles that change the light or the water could be more dense and is doing something to the light.

The light reflects off, but the bent line is not bouncing off at the same angle. So, part of this experiment works with the model, and part doesn't.

For homework tonight we have to compare these 4 scenarios: What is it like for YOU to walk through these things?

1. Air
2. Water
3. Quicksand
4. Wall

My advice for understanding today's lesson! For starters, the important thing we thought about today was why the light did what it did when hitting the water block. Finding the reason why is the hardest part. To figure it out, we have to consider the materials being used and all the different variables that are in play. If we combine new and old things we've learned, we can figure this out.

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As for the homework, think about the density of the different items. Try to find a pattern by picturing yourself walking through the substances.


Hope this helps!

KV