Reflection in Art

This is a picture of one of the art pieces I did this year, I etched the flower into a piece of glass and then put a red background on it and made a wooden frame, it turned out all right, but when Jungle was trying to photograph it for my art portfolio he was having a hard time because of the reflection off of the glass. If you look closely at the bottom of the picture you can see the image of jungle with a hat on and the camera up to his face. 

Reflection occurs when light from a source bounces off an object, like a mirror or a piece of glass, and travels toward your eyes. 

According to the law of reflection, the incidence ray, which is the light ray from the object (in this case Jungle) to the reflective object (the glass), and the reflected ray, from the glass to the viewer's eyes, are equal. Also, light rays are reversible.

When our brain sees the light wave that bounces off the glass, we extrapolate the image backward, so the reflected image is actually behind the glass, or so it appears in our heads. So, in this picture, Jungle's image is the same distance behind the glass as Jungle actually is in front of the glass. 

Object distance = images distance. 

This is a picture of the bells in the bell tower at UC Berkley. I visited Berkley with my family over the summer and we went up the bell tower, there was an awesome view and the bells were really cool too.

Each bell in this elaborate contraption has its own pitch and when played together music is made. When the thing inside the bell is pulled by the strings connecting to it, it hits the side of the bell, producing a vibration. The whole bell vibrates and those vibrations go off into the air, making noise!

The faster the thing hits the side of the bell, the higher the frequency of vibrations. As frequency increases, wavelength decreases. Wave speed is dependent upon the medium the sound wave are traveling through. 

When two waves meet their interaction is called the principle of superposition. The waves pass through each other, but as they meet, the briefly combine. If the crests of the waves match, the add to each other and form a super crest, same with the troughs, but if the crests are opposite then the crest of one wave the the trough of the other subtract from each other and if the waves are identical but 180 degrees out of phase then the waves will cancel each other and you will not be able to see the wave in its medium. 

Aaarrhgg ye matey! Thar be some good physics!

The Iolani water polo team went to California to play over spring break. On our one day not playing polo we went to Disneyland. This is a picture of a pirate band on the street. 

Vibrations create waves and those waves carry energy and information. When the pirates play the keys of their piano thing and violin, they are creating vibrations in the keys and strings of their instruments. The vibrations of the strings in their instruments create sound waves that move through the air. However, the sound created by these waves is much to soft to hear, unless your ear is right next to the strings, especially in the loud environment of Disneyland. So, the body of the violin and the piano thing are there to amplify the sound. The vibrations of the strings cause the bodies of the instruments to vibrate, thereby increasing the vibrating surface area that is in contact with the air, so more waves are being created and everyone can hear! Aarrgh! That be sounding like good physics to me!

Watt meter

Here is my watt-meter & me, blinded by the flash :)

Telephone Wires & Magnetic Fields

These are pictures of the view from either a tree in my backyard or my dad's workshop roof. In the picture on the bottom, on the very left side you can see a transformer box (is that what its called?) for the power lines and in the picture on the top you can a see the telephone wires running across the picture right over the plumeria trees and under the window of our neighbors house. Basically, you can see telephone wires just about anywhere you go. A telephone wire is a conducting wire, so it has current passing through it, and thus it is an electromagnet. An electromagnet refers to a conducting material that gets magnatized only when a current flows through it. So, when current passes through the telephone wires, they are magnatized and exert an magnetic field. The strength of a magnetic field from a wire is directly related to the current passing through the wire and inversely related to the distance from the center of the wire. The direction of the magnetic field lines for the magnetic field of a wire can be determined using the right hand rule #2: your thumb points in the direction of the current and your fingers curl around in the direction that the magnetic field points. The magnetic field lines are always closed loops. 

Bull Riding & Variable Resistors

Last spring break my parents and I went to Oregon to visit my brothers and go snowboarding. On one of the days we went to Mt. Hood and it turned out that is was some sort of family 'western' day and they had a mechanical bull inside the lodge that anyone could ride. So of course we got my brother Haakon to take a turn. In the right upper corner of the picture there is a guy standing at a red podium, this guy was controlling the bull. For little kids, he would make the bull go slow so it would be easier for them. He could control it by hand or just put it on a random setting that would make the bull do random movements. I realize looking back on this picture that the wiring of the controls must of had a variable resistor in order to allow the bull to move faster or slower. A variable resistor increases and decreases the length of the circuit in order to proportionately increase or decrease the the current and thus the speed. Resistance equals resistivity times length over cross sectional area, R= p(L/A). Resistance is directly proportional to resistivity and length, meaning that the larger the length the larger the resistance and vice versa. Resistance is indirectly proportional to cross sectional area. So, when the variable resistor increases the length, it is increasing the resistance and thus decreasing the current, so the bull will move slower. If the length is decreased, the resistance will decrease as well and there will be more current and the bull will move faster. 

Last spring break, my parents and I flew up to Oregon to visit my brothers who are going to school there. We snowboarded as much as possible, so we were outside a lot and it was really cold. As you can see from the picture, my brothers and I wore several layers of cloths in order to stay warm (they would be horrified with this picture because they prefer to act hard-core and wear as little as possible as a sign that they are true 'oregonians' ) Anyway, most of they layers we wear under our outer jackets are fleece and when you are trying to peel off your outer layers after getting home, an electric charge is created. Usually, the fabric of our sweaters would be neutral, however, because the weather was very cold and there was very little moisture in the air, when we peel the fabrics away from each other quickly, a charge is created. Even though they are the same fabric, one steals electrons from the other, like we saw with the tape and the saran rap in lab 21. Charge is always conserved, so if one sweater becomes positive, the other becomes equally negative. The charge that is on the sweaters is not very much and to make the sweater become neutral again you just have to touch it and your body acts as a ground, effectively removing extra charge. 

Banked Turns for Bikes

This summer, my family and I went to California (same trip as the rope swing picture) and when my parents were done paddling we visited some colleges. These two pictures are of the campus as UC Davis. On the right, you can see that there are tons of bikes on campus and this picture was taken in the summer so classes weren't even in session, so during the regular year there would be even more. The picture on the right is a walkway/bike path that winds through campus and you can see that the path is banked as it curves down the hill. Banked curves allow for greater speeds, because on a banked curve centripetal force is made up of a combination of normal force and the x-direction component of friction. On level ground, centripetal force just comes from normal force, so on a banked curve, there is more centripetal force than on level ground. This added centripetal force allows bikers to travel at greater speeds without losing grip and flying off tangent to the curve. This banked path is especially important on a college campus because there are tons of bikers, all of whom are in a hurry and probably hyped up on caffeine :)

Rope Swing!

This summer, my cousin Malcolm and I went to California with my parents. My mom and her crew were paddling in the World Sprints races in Sacramento and Malcolm and I had gone with them to check out colleges. Malcolm and I had a lot of time on our hands because we had to hang out at the lake where the races were for an entire week, one day when we were out paddling we found a rope swing and so we spent a lot of time playing on it. We had a waterproof camera, so this is a picture of me on the rope swing. This picture is an example of circular motion. Circular motion is when an object is rotating about an axis that is outside of the object. Although you cannot see it, the end of the rope is connected to a tree branch, so the axis of my motion is the tree branch. When I let go of the rope, I will become a projectile and no longer have circular motion. This picture also shows kinetic and potential energy. At the moment of this picture, I have both KE and PE because I am in motion and I am above the water, which is my reference point. When I let go of the rope and start to fall toward the water, my KE will increase as my PE decreases. Just in this one picture there is so much physics going on! I never stopped to think this summer that something so entertaining and fun would have so much physics involved. 

The Physics of Ice Skating

In February my friends and I went to the ice palace. In this picture we are skating together with our arms linked and playing the game where you spin in a circular motion with the person on the inside as our axis. The person on the outside of the line gets swung around and when they let go they go really fast. When our arms are all linked, we are generally moving in a uniform circular motion with the centripetal force coming from friction. When the person on the outside lets go, they move in a straight line, instead of continuing in a circle, because inertia causes us to resist change in motion and direction. When we whip the outside person around, we are exerting a torque. Torque = force x lever arm. The force comes from our bodies as we use our arms to push the outside person forward and the lever arm is measured from the axis (the inside person) to the force (which comes from the person next to the outside person), they the torque exerted on the outside person will be larger if you have more people in your line, because then the lever arm is longer.

Tree Bridges & Energy

This is a picture of my friend Sarah and I standing on a fallen tree that we found when we were hiking in Nuuanu. The tree was about fifteen feet off the ground and knowing this information would could have calculated our potential energy by using the equation PE = mv. Our potential energy while standing on top of the tree equals our kinetic energy at the ground if we had fallen off. So we could have figured out the velocity we would have been moving at when we hit the ground at if we had fallen by using the equation PE = KE, mv =(1/2)(m)(v)(v). Knowing our velocity at ground level, we could use the momentum formula, P = mv, to figure out what our momentum would be at the bottom of the fall. Impulse (J) is a force that acts for a certain amount of time and it represents change in momentum, J = (F)(t)= change in P= mv. So we know that the impulse exerted on us when we hit the ground is equal to mv. Luckily, we both have sick balancing skills and neither of us fell, which considering that the impulse would be rather large would have hurt a lot, but it is interesting to know that you can basically calculate how much a fall will hurt with only a very small amount of starting information (mass and height). 

Brothers & Energy

A couple summers ago, my brothers, their friends, and I went out to the Mokolua Islands in Lanikai and jumped off the rocks at Shark's Cove. In this picture, my brother Ian is in the air and my brother Haakon is standing up on the rocks waiting to jump. Ian has both potential and kinetic energy. Ian's potential energy is with respect to the water, as soon as he jumped off the rock, his potential energy started to transfer to kinetic energy, and as he gets closer to the water his potential energy will get smaller and smaller. Potential energy can be negative or positive, depending of the reference level, and because my reference level is the water, Ian will have negative potential energy once he hits the water and goes under. The equation for potential energy is PE=mgh. Haakon is not in motion, so his velocity is zero, so his kinetic energy is zero, because KE=1/2mv2. All of Haakon's energy is potential. However, once Haakon jumps off the rock his potential energy will begin to transfer to kinetic energy, just as Ian's did. In a closed system, total energy is always constant and TE=PE + KE. PE can be negative or positive, depending on your reference point, but KE is always positive. An object only has KE if it is in motion. 

Riding the Physics Wave

This is a picture of my brother Haakon surfing (because I couldn't find any good pictures of myself surfing). My impression of this course so far has kind of been like surfing. When you get out into the lineup for the first time in a day you don't really know what to expect, but you hope its going to be good. I wasn't really sure how I would like physics, but everyone said that if I liked biology then I would probably like physics too, and they were right. I worked hard at the beginning of the year, kind of like paddling to get on a wave, and the first couple of days were a little crazy, like dropping into a wave that is bigger than you thought, but for now I feel like I've gotten on the wave and my main job is to keep my balance and work out the kinks. I guess my only worry would be coming to a topic that I totally don't get, but that would just be like going back to chemistry, and I've learned that you can always get help and figure it would well enough to get by. I have been working hard and focusing and I think that my performance generally reflects that. I actually really like physics right now and I am kind of just riding the wave, trying to enjoy it, and hoping ti doesn't end too abruptly.

Inertia in Kayaking, Newton's 1st Law

This is a picture of the start of a kayaking race, all of the kayakers go from a position at rest to that of movement, meaning that they are providing a net force to overcome their inertia. The foot-wells of our kayaks have holes in them so that if water gets in them it can drain out as we kayak, however when we are at rest eh foot-wells just fill up with water because of the holes. I have always found it irritating that when we start kayaking too quickly from a rest position all of the water in the foot-wells rushes back into the seat area, rather than going out the holes in the foot-wells as it is designed to do. However at kayaking on Wednesday we were doing a workout that included starts, meaning that we had to go from a complete standstill to accelerating as fast as we would, and so of course every time we did a start all of the water from the foot-wells sloshed into our seats. It was at this moment that I suddenly realized it was inertia causing this to happen. Inertia describes the fact that an object at rest will remain at rest and an object in motion will remain in motion, unless acted on by a net force (Newton's 1st Law of Motion). When I am stopped in the kayak, my body, the kayak, and the water in the foot-wells are all at rest. However, when I abruptly start kayaking, I am applying a new force of the outside water, which in turn propels the boat and my body forward. Unfortunately, this net force does not act on the water in my foot-wells and so it stays at rest while the boat and myself move forward. Thus, it is not that the water rushes back into my seat when I start kayaking, but rather that my seat rushes forward to scoop up the water that is still at rest. When this realization suddenly hit me during practice I was pretty excited and I turned to my friend yelling, "its inertia!", but of course she had no idea what I was talking about or referencing. 

Free Fall & Snowboarding jumps

Over spring break I went snowboarding in Oregon with my family. In this picture my brother Ian is in the air after going off a jump. As Ian approached the jump he was going downhill and gaining speed, so his acceleration was negative. When he goes off the jump, Ian has a high initial velocity and he is in free fall, so his new acceleration is -9.8 m/s/s. Ian is moving forward (up), but slowing down so his acceleration is negative. When he gets to the peak of his motion in the air, Ian's velocity will be 0 m/s and then he will start to accelerate again at -9.8 m/s/s, his acceleration is again negative because he is going backward (down) and getting faster. Knowing about acceleration and free fall acceleration can be very important for snowboarders who enjoy spending time in the terrain park. If a snowboarder knows that his or her acceleration will be -9.8 m/s/s after going off a jump, they can clculate how fast they need to be going in order to travel a certain distance in the air and clear any obstacles that might impede a smooth landing. Of course in reality, one's acceleration would be slightly affected by air resistance, however snowboarders are much to rad to worry about inconvenient laws of physics such as this. 

The physics of Kayaking, take 2

This is a picture of me in an ILH kayaking race. As I propel myself though the water with my kayak paddle, I am using two principles of physics, Newton's second and third laws of motion. Newton's second law states that force equals mass times acceleration and his third law states that for every action there is an equal and opposite reaction. To move forward in the kayak, I have to place my paddle in the water and pull backwards, as I pull backwards, I am exerting a force on the water and the water is exerting an opposite force on me. Because the force I applied was backward (or negative), the water exerts a forward ( or positive) force on me, therefore porpelling me forward. Newton's second law allows us to find the acceleration of the kayak bedcause the law states that acceleration is proportional to the force exerted on the object ( the kayak and I), so the harder I pull, the more force I exert, the more force that is inversely exerted on me by the water, and the faster I accelerate. Thus, every time we go out on the beautiful Ala War canal for kayaking practice, the girls and boys on the Iolani kayaking team are using Newton's second and third laws of motion to propel ourselves though the water. 

The Physics of Kayaking