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.

Static Electricity Fun

When my little brother, Ty, was around three or four years old, my older siblings and I liked to rub balloons that we got from parties on his head. It would work really well; we always got hair to connect to the balloon. We knew it was static electricity, but I did not know how it worked. Now I know! So when we rubbed the balloon on his head, we created friction. Electrons from his hair transferred to the balloon, making the balloon negatively charged. From losing electrons, Ty's hair became positively charged. The balloon and his hair were attracted to each other because they wanted to become neutral, so when we pulled the balloon a little away from his head, the hair stuck to the balloon.

The balloon is an insulator, meaning the part that rubbed against his head is the only part of the balloon that was charged. If we had turned the balloon around, the hair would not have stuck to it.

I have another story that is more recent for static electricity. In New York over winter break, the weather was really cold and dry. Arushi and I kept on accidentally shocking each other during the trip. Even if we were wearing all our layers and our coats, we would shock each other. Because objects can keep their charge imbalances longer where there is low humidity, like New York in the winter, we would shock each other as our electrons from our skin or the material transferred everywhere, making everything positively or negatively charged.

Physics in NY

While I was in New York, I noticed many things related to science, like how I could shock other people and vice versa...but I don't know if there's any physics in that, so I choose to write about friction.

I wore boots all the time (because they were warm) but they didn't have a lot of grip on the bottom, so I could slide on smooth tile. Whenever I walked in the hotel lobby where there was tile, there was not a lot of friction between my boot and the floor. It was during the trip when I started to understand why I would not be able to go anywhere controlled if there was no friction. My boot had a harder time gripping the floor and pushing against it to keep moving forward. I had to exert a little more force downward.

I also noticed how great friction is after the zamboni cleaned the ice rink at Central Park. Before they clean the ice, there are a lot of chipped and shaved ice on the rink and the ice itself has marks in it from previous skaters' shoes. It's easier to skate when the ice rink has the marks because they provide friction. After the ice is cleaned, it is smooth. When I stepped onto the clean ice, I almost fell over because my feet were continuing to more without the rest of my body.

The picture is of ice skating.

The Pique Turn

In ballet, we did pique turns across the floor. At the time, I was not thinking torque, but there was certainly a lot of physics at work. So...What keeps a dancer from falling?????

To successfully complete a pique turn, there are certain things that a dancer has to be aware of, such as body placement. We say to bend the knee to push off the ground, pull up, have straight legs, hold the arms up, spot so we know where we're going and to not get dizzy, turn the knee out, hold the head up...
and in physics this would mean...!
In the first step, in order to even get up en pointe and balance, the dancer in the picture has to bend her knee. This provides a force for the dancer to push off the ground. This force is also what helps get the dancer to turn...torque!

By step two, the dancer need to have a center of balance, a center of mass. Everything need to be in line over the box of the shoe (which is the part that the dancer stands on). If the dancer leans to much back, side, or front, then she'll fall because her weight would not be on her center of mass.

During the turn, the dancer can't change any of her body position because that would throw her turn off. If she can hold her placement, she can do multiple turns before landing!

When she lands, she needs to continue to keep everything in line over her center of mass in order to land neatly in a fifth position. By bending her knees, the shock of landing is more easily absorded.