last physics post

The future solution to generate electricity may lie in nuclear fusion. Right now nuclear plants use fission where large atoms are broken down into smaller elements and a mass defect. It occurs in a chain reaction where a neutron collides with the nucleus of an atom causing it to separate. The mass defect is translated into energy by the equation E=mc^2.
Fusion, on the other hand, is the combination of small elements into larger elements. Rather than using a rare uranium element, fusion requires isotopes of hydrogen. Since hydrogen is much more common, fusion can almost be considered a renewable energy source.

Fish

I was looking at fish in the water swimming by my feet when I tried to grab one out of the water. I thought that I was on path to grab the fish when in reality the light was refracting and my hand missed the fish. The index of refraction of the water is much greater than the index of air. Therefore light travels slower in water than in air. The frequency of the light is constant in both mediums.

The angles can be calculated using the formula nsin(x)=nsin(x)where n=the index of refraction.

Music

Music is nothing but physics and waves. A pluck of the string creates a wave of a specific length that produces a sound of a certain frequency. Air can also create a wave frequency like that of a flute, trumpet, or harmonica. The distinct sound of each instrument is caused by the unique combination of different wave lengths that make up the sound. When plotted on a graph, the sound can be as simple as a sine wave or complex like a heartbeat monitor.
Different harmonics can be created by using the same instrument. In this illustration, the tubing shows how different wave lengths can occur from the same tube.

mirror

I was looking at myself in the mirror when I noticed that I could see my whole body in a mirror that was no more than three feet tall. Why could this occur? I could see my feet because the light rays from my feet reflect off of the mirror at the halfway point between my feet and my eyes. The light from the top of my head reflects off of the mirror where it is halfway between the top of my head and my eyes. By increasing the distance to the mirror, a smaller angle of reflection is required and therefore the mirror can be shorter in length.

CD wave diffraction

So I was driving in my car listening to my CD when I realized that I had been taking waves for granted. Sound waves were being amplified by the speakers and reaching my ears. When I would change the balance and tilt of the car, different speakers changed their amplification in order to make the sound loudest at a specific point in the car. I also realized that a CD works by means of light diffraction. A laser is shown beneath the CD and reflected off of the CD back into a laser reader. The bottom of the CD contains grooves that cause the laser to be deflected back at different lengths. The constructive and destructive interferences allow the CD reader to process the light waves into sound waves.

Spoons

I was eating a cup of yogurt when I was staring into the spoon. I appeared upside down in the image. The spoon acted like a concave mirror and produced a real inverted image.The distance of the image appears at the distance x in the equation (1/distance of focus)-(1/Distance of object)=(1/x). The magnification of the object is equal to (height of the image)/(height of the object). The negative value shows that the image is inverted. The magnification is also equal to -(distance of image)/(distance of object).

Renewable energy & global warming

Jeff Mikulina presented ideas for the future of Hawaii's renewable energy crisis. The results of burning fossil fuels have released a lot of carbon dioxide into the air. There is a correlation between the increase of CO2 and the recent increase in global temperature. By using other ways to generate electricity, global warming can be stalled and maybe even stopped.
Mikulina presented the most effective methods of generating electricity in Hawaii. Solar electricity will take advantage of Hawaii's abundance of sunlight. Wind turbines are also very practical. The method that was new to me was the conversion of waves into electricity. Although it is a work in progress, buoys take advantage of what surrounds our islands.
We must all do our part to eleminate our carbon footprint.

Chinese food

I was eating at a Chinese restaurant when several spoons flew off of the spinning table in the center. The inward frictional forces of the spoons were less than the required mv^2/r that would have kept the spoons spinning in a circular motion. The spoons therefore traveled in a trajectory off of the table that is tangent to the rim of the table. The mustard, on the other hand, had a larger normal force and frictional constant that allowed the mustard to stay on the spinning table.
In this perfectly drawn picture, the block has a inward frictional force that keeps it on the table. One spoon flies off of the table at tangency since it does not have enough frictional force. A spoon that has a smaller radius is also traveling at a slower linear velocity than the other spoon.

Relative velocity

I was sitting in the back of a pickup truck while tossing a coin up in the air. At first when I tossed it relatively low, the coin seemed to fall as if I was sitting inside of the truck. It fell straight down in my perspective because it had the same horizontal velocity of the car. To someone on the sidewalk, however, it would look as if it was moving in a parabolic motion. When I threw the coin higher, however, the coin encountered a wind force that slowed down the horizontal motion of the coin. This resulted in the coin landing on the road in back of the tailgate. This drawing illustrates the air flow.
When the tailgate is up, an air pocket is formed. This helps the truck to be more aerodynamic. If the tailgate is down, the air current will have higher pressure above the bed, increasing the drag of the truck in motion.

Circuits

Physics has shown that when wired in parallel, potential difference does not change among resistors. This would be the ideal way to wire a house because a large potential difference will not be needed. Rather than be shared among resistors in series, resistors in parallel will have the same potential difference as the power source. If potential energy is high, power will increase(P=IV). Parallel is also ideal for wiring a house because if something like a light bulb burns out, the rest of the circuit will continue to work. In series, the entire circuit would not work because the circuit is broken at the bulb. The best example of this are christmas lights. If one bulb breaks, you would have to check each bulb to see which one broke if it is wired in series. Finding out which bulb burnt out would be a pain.

Air Pump

According to the regulation bounce of a basketball, when the ball is dropped at the full extension of the arm the ball should bounce to shoulder level. In order to inflate my slightly deflated ball, I needed to do work to move the pump. The work allowed air to be pushed into the ball. Unlike a heat engine where air currents do work, the pump required work and resulted in air change. The volume of the pump is compressed (isobaric) so that air flows out. The ball remained isochoric as the volume never changed.
The ball bounces higher once air is pumped in because the impact with the ground becomes more of an elastic collision with more air in the ball.
By using work to push the handle in, air flows out of the nozzle and into the ball creating more pressure.

Dr. Ignacio's Presentation

Dr. Ignacio was able to share a little insight to being an orthopedic surgeon. It was interesting to see the situations that required a "carpenter" to fix. Surgery required knowledge of not only biology, but many of the sciences including physics. She was able to convey all of the hard work and schooling needed in order to become a doctor in any field. She is an example of following your passion rather than following what others believe is right. She decided to work in the field of sports medicine and orthopedic surgery despite being outnumbered by many males. It was inspiring to see such a successful Iolani graduate.

Radio

Physics continues to play a part in everyday life, even while listening to the radio. Transmitters send radio waves at a specific frequency so that our radios can transfer them into sound. This allows the broadcast of many different channels. Listening to the radio also made me think about the differences between the voices of Perry and Price. What makes their voices unique to themselves? The sound waves that are emitted by their voice box contain different frequencies and harmonies. The graph of this sound wave would not be a definite sine function, but a graph of many crests and troughs.
The Mighty Mo contains many radio transmitters so that it can communicate with all military command.

Speed bump

I was driving in my car when I approached a speed bump. I slowed down and as the car's front two wheels fell, I could feel the frequency of the springs. This meant that physics was at work yet again. As I landed, the car bounced, as if it were in harmonic motion. The weight of the car landing created the force that would make the car no longer exist in equilibrium. This motion, however is not in simple harmonic motion. As shown in this picture, the car's shocks will actually compress a little as it rides up the bump in order to keep the body of the car at a constant level.
Upon landing, the shocks will become stiffer (higher spring constant) so that the car will not bounce. The spring constant of shocks are able to change because of hydraulics and air pressure.

hercules hold

This weekend I had the chance to participate in the world's stongman competition, by watching it on tv. In the event called the hercules hold, contestants need to hold up two pillars with pure strength. They need to exert a tension that provides a torque to balance out the weight of the pillar due to gravity. The height of the center of gravity multiplied by cos(o) multiplied by the weight of the pillar should be equal to tension * sin(s) * height of the chain * sin(o). Therefore the stongest man does not always win this competition. The one whose body fits the event the best will win. A man with a shorter horizontal span will decrease the ammount of tension required and the man who is tall enough to hold the chains parallel to the ground will maximize the tension value.

pool

This weekend I went swimming in a pool. I jumped in and with no surprise, I felt much lighter. This was due to the buoyant force. The volume of the displacement of pool water multiplied by the density of pool water and gravitational force was equal to the buoyant force. My weight minus the buoyant force was equal to my weight in the pool.
If I floated instead of sunk in the pool, then the buoyant force would be equal to my weight.

spoon levers

I was eating ice cream when I noticed that using a spoon required physics. The a scoop of frozen ice cream needed to be pried with force from a spoon. By using the side of the bowl as a fulcrum, I applied a downward force with my hand. Once there was enough force to overcome the static friction force of frozen ice cream, the small scoop was lifted. If I moved the handle of the spoon farther away from the fulcrum, it would have made lifting the ice cream easier since less force is necessary because the distance between the fulcrum and my hand increases and the distance between the fulcrum and the ice cream decreases. If the handle of the spoon is closer to the fulcrum it will be harder to lift the ice cream.

Dizzy

So I was sitting on my chair in front of the computer not knowing what to write about for this weeks journal entry. I began to spin in the rolling chair and I realized that that was actually physics. I stuck both of my feet out parrallel to the ground and although it was moving at the same angular velocity, their tangential velocity was more because the radius from my toe to the center of the chair was larger. I began to spin faster and faster. My toes now had a higher tangential acceleration but the same angular acceleration. I began to count in radians the number of spins that I could do. 2 pi, 4 pi, 6 pi, 8 pi, 10 pi, 12 pi . . .



no that is not fire. This is turning into a biology blog.

Jumping in Sand

Why is it harder to jump higher in sand than it is to jump on a court? This is the question I began to ponder as I grew exausted from playing beach volleyball. I then realized that Newton's Laws were the reason for my exaustion. In order to jump, the legs need to exert a force on the ground so that the ground exerts and equal and opposite force to push the body in to the air. In the gym, nearly all of the force exerted by the floor is transfered to the jump. On the beach however, tiny sand particles cushion the force of the jump by spreading outward. Therefore not a lot of the force is transfered to the jump because some force is needed to push the sand particles outward. The static friction of the sand is also relatively small compared to the solid, one-pieced court.

Halloween Humpty Dumpty

With Halloween coming up, unopened candy litters my house and so to tidy up the mess, I eat the candy. I ate some hershey's chocolate first and then some skittles. Finally I tried the M and M's and physics kicked in. When I was opening the bag of M and M's, all of the different colors fell to the floor. The impact caused many of the hard candy shell to break, sending small pieces in all different directions. The conservation of momentum tells me that the momentum of each M and M is the same as the momentum of the pieces that it broke into. The mass of the M and M multiplied by the velocity right before impact is equal to the sum of each shard's mass multiplied by its own velocity right after breaking.
Humpty Dumpty?