larger than life

We're learning about how things are magnified, so I put up these pictures of this bottle up. They're both taken from the same distance, so the characters on the bottle definitely get larger because of the glass. Because the characters get larger, the glass can't be acting as a diverging lens, because those only create smaller images. And as a concave lens, the letters must be within one focal length of the glass because that is the only time the image gets bigger and stays upright. However, because it is within one focal length, the image is only virtual (it can't be produced onto a screen). Light doesn't go through the lens and merge at one spot, but the eyes work it out so that the image can still be seen. Appearances are definitely deceiving.

difference between Painting and Physics

In painting, red, blue, and yellow are supposed to be the primary colors that are mixed to make other colors, but this is not true in physics. In physics, cyan, yellow, and magenta are what make up all the different colors. By substitution, these colors not only produce the painting primary colors, but others as well. It's a hard concept to accept, but after some thought, I realized it is true. Although the painting primary colors are taught to kids and people in art classes, it is highly unlikely that they will only use red, blue, and yellow paint for their artwork. Instead there are colors such as pthalo blue or payne's grey, colors that would be very difficult (if not impossible) to make with only the painting primary colors. Even printers only have cyan, magenta, and yellow ink, but can produce all sorts of colors, so the painting primary colors must be fake. However, it's hard to think about how we use the cones in our eyes to help us see colors when mixing, which is probably why the painting primary colors are the more popular of the two.

am i hearing things?

My dad just bought headphones as a gift for my grandmother and I didn't really think about them. However, I heard this irritating high pitched squeal one morning, but when I asked my parents if they heard the noise they said they couldn't hear anything. When I found out the noise was coming from the headphones I told my dad and he thought I was messing with him because he couldn't hear anything. Apparently the frequency of the noise is too high for either of my parents to hear anymore. Like we learned in class, humans can have a hearing range from 20 Hz to 2000 Hz, but it varies from person to person. Once a frequency is outside of a person's range, they no longer hear it. However, since I can hear it, my grandmother's dog probably can, too.

wave action

Ocean waves have the same characteristics as the waves we are learning about right now. The velocity of a wave stays constant, even when frequency or wavelength changes. Ocean waves are both transverse and longitudinal waves because particles on the wave move both perpendicularly and parallel to the direction of the wave. They also pass through one another. Ocean waves are example of waves that are easier to understand than sound waves, because they can actually be seen and observed. An example of wave observation would be when people pick opihi. They count the big waves, which normally come in threes, and then go down to pick during the lull that comes right after the last wave. The pickers still have to watch the waves, but the frequency and pattern of the waves stays relatively constant. I'm not really sure why they come in threes though.

Sound waves

During spring break, a bunch of us went to waikiki for karaoke and although I didn't know much about the subject at the time, there were a lot of sound waves. Higher voices have a higher frequency. However, because frequency is equal to the reciprocal of the period of the wave, higher voices have smaller periods. Even when frequency changes, it does not affect the speed of the sound wave. This is because speed=frequency x wave length and frequency and wave length have an inverse relationship. This is why two people can be singing a duet at different frequencies, but their voices will be heard by others at the same time. So there really is physics even in singing.

Overload...

Well, it's been awhile since we've talked about these things, but I just found what I think is the circuit breaker for my apartment. At first I thought they were fuses, but they don't seem to have anything that is easily replaced and the switches go on and off. These switches turn off when the current going through the wires is too high. This is to protect the house from possible fires that could occur when too much current goes through a wire and burns it up. There are many switches because each one is in charge of the current flowing to a different area. I think this means that the system is in a parallel because that way one switch going off won't affect the rest. (Luckily, we've only had to use the circuit breaker once from what I can remember.)

wonders on a refrigerator

Well this lesson we're learning about magnets, which is something I never thought I would be able to relate to physics. In fact, before this chapter, I never even thought about why magnets are able to hold photos down by sticking onto things such as a refrigerator. The magnet has a north pole and a south pole (which are the front and back sides of it) and each pole is attracted to its opposite. This is what allows magnets to stick together at times. However, magnets can also stick to certain materials (such as metals) even when the objects are not magnetized. However, just like in the lab, there is a certain place where the two poles meet that does not allow for other object to be attracted. This place makes it easier to distinguish between magnets and objects that can stick to magnets. It's kind of funny how just going for a late night snack can remind me of physics.

light intensity

Since we had labs to do on light bulbs and resistance, I finally noticed that I actually did have a switch in my house that had a variable resistor. When you turn the knobs clockwise, the intensity of the light increases. This is because Resistance varies directly with distance, so if one charge is connected to the needle and the opposite charge is connected to the left end of the knob, as the distance between the two grows, the resistance increases. V/R is equal to the amount of current at a point, so when R increases, the current decreases. This decrease in current causes the power supplied to the bulb to decrease because P=IV. Less power means that the light will be less intense. If we didn't go over this in physics, I never would've noticed that I had this kind of switch, let alone figured out just how it's able to vary light intensity.

shoes and carpets

Well, I've never actually gotten shocked at home from static electricity, but I remember all the times it happened in Las Vegas. Pretty much from the time I walked into the hotel I started getting shocked every time I touched someone else or a door knob. I drag my feet a lot so I must have been picking up a lot of electrons from the carpet that wanted to be released because the body naturally wants to be neutral, not charged. Besides dragging my feet, the weather conditions over there probably helped build the static electricity to levels higher than they are in Hawaii. The humidity over here must allow the electrons to leak off at a faster pace than in Vegas. I guess all I have to do is stay away from really dry or cold places.

leftovers...

Well, everyone was out at a Superbowl party and left me home to fend for myself so i ate leftovers. That's when I saw the saran wrap on the bowl and remembered static friction from the last test. When rolling the wrap out of the container, electrons are pulled from the level below and the top layer is positive, which is why it sticks so well to itself. This is because the posititve charged side and the negative charged sides are attracted to each other. And especially because the refrigerator is so cold, the saran wrap must stick to it better (because the physics room needed to be colder for the lab to work better). Then, when I crumpled it up and threw the saran wrap into the trash, it didn't stick to itself because the electrons from the negative side transferred to the positive side so it was no longer polar.

car shock

As I was getting out of the car today, I got shocked again. The feeling is just like the zap from Vegas when you accidentally bump into someone. When two objects touch, if one has a charge and the other is neutral, electrons will move to whichever object is more positive. This is because objects want to stay neutral. In the situation with my car, I'm pretty sure that I'm neutral and the car door must have a negative charge. I'm probably neutral because I don't remember doing anything that would cause me to gain or lose electrons. The rubber on the car door might have gotten some electrons from the metal part of the car when I opened the door, giving it a negative charge. (The rubber is an insulator so electrons would not flow throughout all of it.) The electrons passed from the door to my hand, which is why I think that the zap occured. (But it's weird how my car only seems to shock me, not anyone else that rides in it.)

Flying Fish...

This was from Winter Break, and the story behind it has quite a bit of physics involved. Me and my friend were fishing on the Big Island and she caught the first fish. Since the fish wanted to get away with the bait, it tried to swim away. This caused tension in the fishing line (considering it was only a bamboo pole). However, the force with which she pulled the pole was great enough to allow it to overcome rotational inertia and begin rotating (clockwise in this picture). This also made the fish, still attached to the bait, go in a circular motion (just like the ball and string exercise in class). However, it couldn't hold on long enough, and ended up flying in a tangent and back into the water on the other side of the rocks. In the end, she lost a tasty snack, but she gained an understanding of tension, rotational inertia, and tangential vectors.

Bridge Balance

I found an example of torque just in time for the upcoming test. The bridge is really old and falling apart, but its weight is still being held up by the normal force of the ground on both sides. The weight is focused in the CM (center of mass), which probably isn't in the middle of the bridge since parts of the fence have already fallen off. The weight has to be supported by the ground, because otherwise the it would keep on falling. Besides the forces cancelling each other out, no matter where the fulcrum is, the torque exerted by the forces also have to cancel each other because otherwise the bridge would be rotating instead of standing still. (Torque is equal to forcexdistance from the fulcrum). The balance for the forces and torque exerted are the reason why this bridge stays still.