Tuesday, October 19, 2010

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.

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