Oct. 12-16

I think we started the week by learning about light and how we see colors. We had to answer the question "What occurs when light hits a surface?" The correct answer is that it sometimes reflects, sometimes refracts, and sometimes it is absorbed. We started talking about color, and said that white light is all colors, while black is none. Ex. of how we see colors: White light hits a green object, and the green light is reflected off while the other colors are absorbed. The color that the object is gets reflected off, so we see that color, and all the other colors are absorbed into the object. This is very important because colors are used every day, and it is important that we see them.

For homework, we each had to make a rubric to score ray diagrams, and the next day we used them to rate ray diagrams that people made. The highest number of points I had for each category was 3. For the first one, I gave it 0 for the direction of arrows because it didn't have and arrow points, 3 for neatness, and 2 for accuracy because it should have shown more rays. The second I gave perfect. The third I gave 2 for direction of arrows because the arrows were all going in the same direction, I gave it 3 for neatness, and I gave it 2 for accuracy because the rays were not going everywhere they were supposed to. For the fourth, I gave it 0 because the rays had no arrow points, 2 because it was somewhat messy, and 1 because the rays were curvy. We decided that all ray/wave diagrams should: have the waves be perpendicular to rays; have spacing of waves equal to speed; have arrow points on rays; have rays and waves show the direction; have objects labeled; have waves and rays following the law of reflection; and have waves refracting correctly. This is important because we would most likely get points taken off our tests or quizzes if our ray or wave diagrams are not correct.

Then for homework we watched a short video about a high density slinky and a low density slinky connected that had a wave go through it. My hypothesis before I watched it was that if a wave travels from the high d slinky to the low d slinky, then the wave should start slow and small then get bigger and faster when it gets to the less dense section, and vice versa. That is exactly what happened. The waves through a slinky is like waves going through different mediums with different densities. This is important because waves react differently when they go through different densities.

Then, another time, we stared talking about how we could not see all types of waves. The only type we can see is visible light. Other types of waves are ultra violet, infrared, microwaves, x-rays, and gamma rays. These are important because we use these waves daily. Visible light is used to see, microwaves are used in a microwave, infrared rays are use in a tv remote, and x-rays are used in x-rays at the hospital.

Then we stared talking about prisms. We don't see a rainbow when we shine a laser in the prism because that light is only red. But when we shine white light we can see a rainbow because the colors refract at different angles, and they separate. we also learned that light can reflect inside too, so when we shone the laser at the prism, it went everywhere.

On Friday, my class had to take the unit test on light.