Sunday, May 11, 2008
So, as I was sitting at my computer, trying to figure out what to write for this week's entry, I happened to notice that the screen of the Mac computer was acting like a mirror. I could see the part of my house that was to my left. The incident ray of light bounced off the computer screen, and the reflected ray traveled to my eye, allowing me to see the image in the picture. The image appears as far back as the actual scene is from the computer screen. The image is also actually behind the "mirror", as we learned in class. As you can tell, I'm kind of running out of things to write about...
Saturday, May 3, 2008
In the picture, the yellow egg that Madi is holding appears yellow because the red and green cones in our eyes are stimulated. Since the sunlight is made up of red, blue, and green light, to appear yellow, only the blue light is absorbed while the red and green light is reflected. At Easter, I also remember that my cousin put his egg in every single color of dye, and it turned a really disgusting brown. Thanks to physics, I now know that mixing paint colors and light colors are different. In that lab we did, when we combined all the colors, the paint also turned an equally gross-looking brown. Only if you mix magenta, cyan, and yellow LIGHT together, will it produce black.
Sunday, April 27, 2008
In order to celebrate my LAST ORCHESTRA CONCERT, I guess I will do a journal entry on the physcis of playing the violin...When you pluck or bow a string on the violin, you create standing waves. If you place a finger on the string (like I did in the picture), you shorten the length of the string, decreasing the wavelength but increasing the frequency of the fingered string. Playing a note an octave higher means you doubled the original note's frequency. When you tune, you also try and match the frequency of the note being played so that you don't hear beats. Playing a piece "spicatto" even involves torque because you must play the notes at the bow's center of mass so that the bow can rotate and move freely.
Thursday, April 10, 2008
This is a metronome (obviously). Besides setting a steady beat that helps me to play my violin in tempo, it also has a setting that plays the note A which allows me to tune my instrument. I never realized this before, but on the dial, right below where it says "A", it says 440 Hz, the frequency of the note A (!!!). This past week of physics has also made me realize why tightening the tuning pegs on my violin increases the pitch of the string. The wave speed of the string increases with the increase in tension. By winding the string around the tuning peg, I am increasing the tension of the string and increasing its wave speed. Increasing the wave speed of the string also increases its frequency. This higher frequency is picked up by my ear as a higher pitch.
Sunday, April 6, 2008
This isn't the best picture, but I had to (yet again) post another picture of a lame ticket stub because I forgot my camera (!!!). So, this weekend I went to the Chris Tomlin concert with my Youth Group from church. It was my first time at a, umm, "religious" concert, but I was surprised to find that I enjoyed it. The electric guitars used electromagnetic induction to produce the music. A permanent magnet magnetized the guitar strings so that when the strings vibrated back and forth near a coil, it induced an emf in the wire. The current in the wire created a signal which was transmitted to the loudspeakers to amplify the sound. I could hear the music because of sound waves which were created by the oscillation of the loudspeakers. When the sound waves reached my ear, they vibrated my eardrum, generating signals that were transmitted to a part of my brain that interprets them as sound.
Saturday, March 15, 2008
So after we did the Genecon lab this week, I finally figured out that this pig flashlight is not just a normal flashlight...It's a generator too! I always used to wonder why it had this weird handle-thing that occasionally popped out of its side. Thanks to the lab we did this week, I now know that the handle probably makes a magnet spin past coils of wire (or vice versa) that are connected to the lightbulbs in its nose. The change in the magnetic field induces a current that allows the bulbs to light up. This is an example of a generator and a motor (I think).
Sunday, March 9, 2008
This is obviously a picture of my ticket stub from the Cartel concert I went to this weekend. I only posted this lame picture because I didn't want to take my camera into the mosh pit and get it trampled and ground into tiny pieces. Being in the mosh pit is pretty fun except for the fact that there are random people bumping into you with their sweaty bodies. And there is the potential hazard of getting kicked in the head by people who are trying to crowd surf. The crowd surfers actually became human projectiles. They were launched by people in the back and caught by the security guards in the front. It actually looked pretty fun...With people pushing me from all sides, I kind of felt like an electron in a wire with too much current :) Corny analogy, I know...Anyways, all the momentum from the people in back of me also propelled me into the person in front of me, creating this big chain reaction of forward motion. My friend actually fell down twice because she had too much momentum carrying her forward but no one in front of her to pass it on to...
Sunday, March 2, 2008
This weekend I went hiking up to Makapuu Lighthouse. We saw a lot of whales...well, their spouts at least, and a few of them even breached! Although I couldn't get any good pictures of the whales we saw, I did get a photo of the lighthouse from the very top. It looked like there was one huge bulb inside...If there is just one bulb, it must have a really thick filament to allow for all the current that produces that much power. My cousin Suger also had a birthday party this weekend (Hannah Montana theme by the way), and my brother was balancing his can of soda on the table and I all I could think was...hey! Center of mass!
Sunday, February 24, 2008
Sorry this picture is sideways, but I haven't figured out how to rotate pictures on this computer yet. Anyways, this is a picture of the Embassy Suites, the hotel that we stayed at last weekend in Oregon. When I saw this picture, I couldn't help but think of circuits. All the lights in the picture are pretty much the same brightness. I'm guessing that the lights in this hotel are connected in parallel and not a series circuit since it would be a lot easier to fix if one of the bulbs went out. Being in a parallel circuit means that although the voltage difference is pretty much the same, the current is different at different locations on the circuit. Thanks to the lab that we finished on Friday, I know that the current is not the same because it's split between the different branches of the circuit.
Saturday, February 9, 2008
These are pictures from our Alaska trip (yet again) when we went white water rafting. I was pretty scared at first because being the clumsy person that I am, I was sure I was going to fly out of the raft once we hit some kind of turbulence in the water (hey, that involves collisions and projectiles!). I made it though (thank God), and it wasn't as bad as I thought it was going to be. Since it wasn't hard-core white water rafting (we didn't even have to wear helmets), going through the rapids was actually really fun! It was kind of like being on one of those rides in Disneyland (except without seat belts). Anyways, on to the physics of it all...The force of the river gave our raft enough momentum so that we didn't have to do any paddling, even as we floated through the calmer parts of the river. I guess torque was also involved because our raft was pretty stable and no one fell in the water. The steersman of our raft also had to use torque and leverage through his paddles to maneuver the raft around these huge rocks sticking out of the water (when I first saw one of those things, I was sure I was going to die). Our suits also made me think of the last few chapters we studied because they insulated us from the freeeeeezing water, like how a piece of rubber or wood can protect someone from getting shocked. Looking back at the pictures, our suits also kind of made us look like weird spacemen or aquatic divers or something....
Sunday, February 3, 2008
This is from our family's annual Christmas play. The foil helmets that the boys are wearing are good conductors of electricity. That means that if a potential lightning bolt were to suddenly strike, my brother would be the one who would get hit (haha) because he's the tallest. If an electric charge were to be applied to the foil on the tip of the spear, my cousin would probably not get severely shocked since the spear has a wooden handle and wood is an insulator.
Sunday, January 27, 2008
These are pictures from New Years Eve. A lot of projectiles were involved...the ground bloomers we were all throwing in the air, the sparks from the fireworks, and the bottle rockets my cousins were shooting out of a pipe. In the second picture, although it looks like we're all about to fall, everyone was able to balance because our CM's were all supported. By leaning on each other, we were all able to widen our support areas, which helped us to stay balanced.
Tuesday, January 22, 2008
This is during Christmas break on my family's annual gingerbread-house-building day. So what does gingerbread have to do with physics? In class we learned that "all things are attracted to one another". Due to gravitational force, everyone's roofs kept sliding apart (despite the super sticky frosting we used). Because of physics, I now know that the same gravitational force that pulled the gingerbread down is also the same force that pulls the moon towards earth...Wow...Anways, all the candy we loaded on the roofs also exerted downward forces on the gingerbread houses and the gingerbread houses exerted upward forces on the candy. Everybody finally got their roofs to stick, and I have to say, they ended up looking pretty impressive =)
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