Balloons: Color and Reflection

In physics class, we have discussed many things which relate very easily to life, such as color and reflection.

I have found color and reflection in the balloons that were part of the centerpiece for Junior Prom. The white light from the ceiling lights hit the red balloons. The balloons absorb the green and blue components of the white light, and reflect the red component to my eyes. That is why the balloon is red. For the black balloons, they appear black because they absorb all of the colors and do not reflect any color. This would be considered the absence of color, so in a way...black is not a color?! The yellow star balloon reflects two colors: the red light and the green light. Surprisingly, red and green combine to make yellow.

I took the balloons home :) My friend and I looked at the red balloon and saw our faces in them. Also, we could see that our faces looked different because the balloon is curved. The light from our faces reflect to the balloon and bounce off to our eyes. Light always takes the path of shortest time and travels in straight lines according to Fermat's Principle. This means that the light from my face knows which angle to bounce off the balloon in order to reach my eyes as quickly as possible.

This picture is my second picture on this blog that's from a camera!

On the Freeway

Once in a while, an ambulance has to come through traffic on the freeway. This was the case for today.

From far away, I can never tell what direction the ambulance is coming from, but as it gets closer, I realize that it's coming from behind me. This is due to the Doppler Effect because as the moving object (the ambulance) is coming to the stationary object (me in the car that has pulled over), the frequency from the siren goes higher. The equation used would be the velocity of the sound's frequency divided by the frequency's velocity minus the velocity of the ambulance. Then all that is multiplied by the actual sound's frequency to get the frequency that I would hear as it approaches. Thus the sound seems more high-pitched and loud when it is coming toward me. After it passes me, the frequency that I hear becomes less.

Clarinetting and Physics

Whether I am playing by myself, in band, or at a concert, I am applying physics as I blow air into the clarinet.

Sound in the clarinet is made by oscillating motion or air flow. The reed is bendy and is normally controlled by resonating air in the clarinet. Once the air in the clarinet is vibrating, some of the energy leaves through the bell and any open holes (keys) The vibrating column of air flow determines the frequency and in effect the pitch. A sound wave can travel down through the clarinet and reflect and go back up. The longer the clarinet, the longer it takes to make a round trip. The length can be changed by lifting my fingers off or on keyholes and thus shortening or lengthening the distance. If all the holes are closed, the pitch is at its lowest (the lowest frequency). Frequency is the number of vibrations per second. The lower the note, the less vibrations there are per second. The higher the note, the more vibrations there are per second.

If I squeak (which is most likely on accident), that means the reed vibrated at its own resonance. By putting my lower lip on the reed, I am dampening the strength of the reed's natural resonance.

Describing exactly how the clarinet works is complicated, especially if I tried to add in the register key which takes the clarinet up another octave, so I am not sure if I said everything right.

On the Side of the House

My electric meter happens to be on the side of my house above a steep set of stairs. I had seen it all the time and wondered what it was when I was younger, but I forgot it existed in recent years.

When we use electricity, the current is sent through the electric meter. The current first goes through a coil, making the coil become an electromagnet. The electromagnet induces a current in the second coil. The two coils's magnetic field lines enforce each other to make a disc spin. This disc turns the wheels of the five mini-sized counters. The electricity current which ran into the electric meter continues through and goes into the house to power the appliances, like the refrigerater. That is how the electric meter works. It is strange that I have never seen the meter reader come around.

This picture is the first on this blog from a camera. My mom let me use her camera and I was able to figure out how to put the pictures on the computer! yay.

In My Locker...

In my locker are four magnets! Two of them can connect to make a hippo and the other two can connect to make a cow.

In any case, magnetism made me think of my hippo and cow. The half-hippos and half-cows create a magnetic field and exert a magnetic force allowing them to stick to my locker and each other. In them are magnets with north and south poles. One side of the hippo has the north pole facing outward while the other side has its magnets' south poles facing outward. I figured out that I could stick a north side of the hippo with the south side of a cow to create a hippow. If I try to stick a north side hippo with a north side cow, they repel because the magnetic fields repel each other. In a magnet are domains, which are large groups of atoms whose spins are aligned. A magnet cannot have a north pole without a south pole.

The picture is not accurate on their sizes and looks... I have a half-hippo sticking to the hangers. They are very cool so whoever reads this should come to look at them sometime :)

Burnt Out

As I was trying to figure out what to write about for my physics blog, I happened to look up and stare at the chandelier. I noticed that the light bulb was burnt out and when I thought about the light bulb, I thought about why the light bulb was no longer bright like its companions.
Inside a light bulb is a filament that glows from heat energy from excited electrons that gets converted into light energy as those electrons are travelling through the filament. The filament has a high boiling point so that it can take more electrons before the electrons are converted into light energy. The filament is very twisted to create a higher resistance so that the electrons have a harder time travelling through it. Resistance relies on the wire's length, cross-sectional area and the resistivity of the material. The filament is actually very long because it was curled tightly. At some point the filament is no longer usable, making the lightbulb die.

All of the other lightbulbs are very bright. They have a current running through them. Current depends on the voltage difference and the resistance. Current can also be calculated by the charge in coulombs divided by the amount of time.

In the picture, I didn't draw all of the light bulbs.

Scary Physics

When I plug something in, sometimes I see a small bolt of lightning coming from the electrical outlet or I hear a pop kind of sound. It was kind of scary to see the electricity fly like that, but I know for sure that I am safe as long as I don't touch the metal. The metal conducts the electricity, but the electrons don't travel all around the plug part because the part I hold onto is made out of plastic. Plastic is an insulator, meaning the charge does not move to other regions of the object. If it is a colder day, then I'll see the bolt, but if it's less cold then I'll hear the pop. When it is colder and the humidity is low, objects can retain their charge imbalances longer, so the need to become neutral is greater. The outlet gives the excess electrons happily to my plug.
If I were to touch the metal part of the plug as I put it into the wall, I would get electrocuted as my fingers received the electrons. Depending on the voltage, I would receive a certain amount of joules per one coulomb of electrons, which is 6.25e18 electrons. So if the voltage was 200 volts, then I would receive 200 joules of energy per one coulomb of electrons.
It's kind of hard to see my bolt of electricity in the picture, but it's there.