more unit 10

The last day of unit 10 talked more about reflection and refraction. Refraction is the change in the direction of a wave due to a change in speed. Reflection is when a wave bounces off of an interfering thing. The picture is of a laser beam reflecting off the lens of Sho's camera. The beam hits the lens and reflects in a different direction. Unlike reflection, refraction is when the speed of the wave changes usually due to it passing through different materials. Mr. Blake's example of torching really showed me a lot about refraction. When you go torching, you walk around with a spear and light, and spear fish that are attracted to the light. However, the refraction caused by the water makes the fish appear to be further away than it is. I have first hand experience of this. The first time I went torching, I missed every time because I though the fish was in line with my eye sight when in fact, the refraction of the water on the light caused it to be closer. I thought refraction was interesting, and have noticed it all around me.

unit 10, lasers and stuff

Today we learned about lasers and light reflection. The picture I have is of a laser beam reflecting off my hand. The types of reflection we learned about were diffuse and specular. The reflection of the laser on my hand is a diffuse reflection. This type of reflection occurs when the surface the light is reflecting off isn't smooth relative to the wavelength of the light. This causes the waves to scatter instead of reflect in a uniform fashion. This can be seen when the area around the impact of the light is lit up with the color. A specular reflection is when the light waves bounce off the surface without scattering, this is because the surface is smooth relative to the wavelength. Some of these surfaces include mirrors, or calm water. We also covered blending light. The primary colors of light are red, blue, and green. Not red, blue, and yellow. When you combine these colors, you get other colors like yellow, cyan, and magenta. Overall, today was a pretty cool lesson. The characteristics of light are different then what I would've imagined.

Unit 10 (EM, visible light, light properties)

Today we learned about light and electromagnetic waves. One of the things we learned that I found interesting was how light reflects off objects. You can't see actual light, what you see is the light reflecting off of objects. The picture I have is of a green pillow. The pillow is actually every color but the exact shade of green that can be seen. Since it isn't that color, the shade of green is reflected back to the eyes. I also learned more about light years, it is the distance that light travels in one year. Overall, this has been an interesting unit, a lot of what we learned has been confusing in a cool way. I am looking forward to learning more about it tomorrow.

Unit 9 waves and sound (again)

Today we learned more about waves. One of the focuses of the day was standing waves. This type of wave has nodes and antinodes. The picture is from the experiment we did involving the vibrating rope. The rope is experiencing standing waves. A node is where there is the least movement, it is at each end of the rope, and at various places throughout the length of the rope, depending on the frequency. The antinode is where the rope moves the most, unlike nodes, these are not at each end of the rope, however, they are spaced at various places throughout the rope depending on the frequency. A standing wave is created when, in this case, a rope is experiencing vibrations on one side, and is attached to a solid point on the other. The wave travels down the rope, and reflects off the other side, it returns exactly opposite of the original motion. At certain frequencies, the waves will line up creating nodes and antinodes, or in other words, standing waves.

Unit 9

     Today we learned primarily about waves. The waves we learned about were not necessarily ocean waves, although they do apply. A wave is a movement to and fro with a swaying or undulating motion while remaining fixed to one point. An ocean wave is caused by some sort of vibration, which is An oscillation of the parts of a fluid or an elastic solid whose equilibrium has been disturbed, or of an electromagnetic wave. The video I have was shot by a friend of my Dad's at the surf spot Jaws on Maui. It is known as the biggest ridable wave. The swells that role in at jaws, or any beach for that matter are waves, and carry the characteristics of what we learned in class. An entire wavelength could be measured from the top of one wave to the top of the wave behind it. In class, Mr. Blake talked about the way's people measure a wave, the common way accepted around the world is to measure from trough to crest, this measures the face of the wave. I as well as many people in Hawaii measure the back of the wave, this is the same as measuring the distance from the amplitude to crest, it is about half the size of the face. The surf spot shown in the video is best when it has 40+ ft faces, or 20+ ft when you measure from the amplitude. Overall, this lesson was interesting to learn. Being one who spends a lot of time at the beach, I understand waves fairly well. 


Video: http://www.youtube.com/results?search_query=Panasonic+GH13+%2B+JAWS+11-2-10+%2B+Zoom+H4n+%2B+Redhead+Windscreen&aq=f

Bottle Rocket day 2

 
 Today was the day we launched our rockets. The goal was to get around 10 sec of hang time. My rocket, the one in the picture, got a best time of 10.7 seconds, even thought the parachute didn't fully deploy. Using the orange cone as a nose cone worked really well. It was shaped in a good shape, and had room inside to stuff the parachute. Unfortunately, the only flaw was that the parachute would often get stuck in the nose cone and not pop out to save our rocket. One of our launches ended up with the nose cone buried literally 4-5 inches deep in the ground. On our last launch, we left part of the parachute hanging out of the nose cone, the parachute ended up fully deploying, but it slowed down the rocket on the way up by causing more air resistance. We filled the rocket to about 1/4 full, and attempted to get between 80-100 psi before launching.

     From this project, I learned about the importance of balance and the movement of projectiles. Once our rocket was launched, it became a projectile. In order to achieve the best flight, we had to balance the rocket so it would fly straight, the fins greatly helped this. The mass in the nose cone helped keep the rocket on track, but if it didn't deploy the parachute, it fell super fast. Overall, I didn't learn a large amount of new physics, but it was good to see what we had learned put into practice when shooting the bottle rocket.

Bottle Rockets

      This week we have started our bottle rocket project. The goal of the project is to get a rocket to stay in the air for at least 8 sec, but ideally 10 sec. There are many factors that go into play when going for maximum time. Weight, balance, stability, and a parachute are four of the main factors.
     The weight of the object is important, if the object is too heavy, it will affect the flight, but the additions to it cause the weight to increase. Weight distribution is also important to the flight of the rocket. The nose cone needs to have a mass in it, this will stabilize it and cause it to hopefully fall off and let the parachute deploy.
     Balance is similar to weight distribution, but involves the placement of each additional item on the rocket. By making the rocket balanced, it will prevent it from going any where but up.
     Stability can be increased by the addition of fins. Fins help guide the airflow around the rocket. This keeps it from spinning or turning in the air. The fins should be equally placed around the rocket.
     Finally, the parachute is crucial to keeping the rocket in the air. The rocket goes up fast, and without the parachute, returns to the ground fast. By causing a slower descent, the hang time will be increased. Today, corey and I had problems getting out parachute to deploy, the pressure of the air on the nose cone prevented it from falling off the rocket. We are going to solve this by putting supports under it so it can't fall any further down the rocket. If the parachute deploys, it will cause the time to greatly increase.
    Overall, this lab is a good test of our understanding of how physics will affect the rocket. It will be interesting to launch our rockets more tomorrow.