nathanstack15

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nathanstack15 last won the day on December 17 2016

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About nathanstack15

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  1. I've never heard of Cherenkov Radiation before. Very cool!
  2. HBP

    Looks painful!
  3. A couple days ago, a Swiss skier named Andri Ragettli landed the first ever 'Quad Cork 1800', in which he flew 38 yards off of a jump in Italy, making five full rotations and four head-under-body spins. The video of the jump is attached below. The true difficulty of landing such a trick is very clear when considering the physics behind it. First, in order to be in the air long enough to perform such a trick, a skier needs to gain a great amount of kinetic energy as he descends from the top of the hill. In order to do this, the height of the top of the hill should be maximized so as to maximize gravitational potential energy, which is then converted into kinetic energy as the skier descends. Additionally, once Ragettli is in the air, you may notice that he crouches down low, which minimizes the rotational inertia of his body, allowing him to experience a more rapid angular acceleration. After Ragettli rotates multiple times in mid air, just before landing, he straightens his body, which increases his rotational inertia. Since angular momentum is conserved, an increasing rotational inertia causes a decreasing angular speed. Therefore, by straightening his body, his angular speed decreases, making it easier to stick the landing.
  4. I have played the saxophone for a very long time and really enjoy it. Although I have played it for so long, I have never learned the physics behind how blowing on a little piece of wood generates sound. In making a sound on the saxophone, one blows air at a high pressure through the mouthpiece. The reed controls the air flow through the instrument and acts like an oscillating valve. The reed, in cooperation with the resonances in the air in the instrument, produces an oscillating component of both flow and pressure. Once the air vibrates, some of the energy is radiated as sound out of the bell and any open holes. A much greater amount of energy is lost as a sort of friction with the wall. The column of air in the saxophone vibrates much more easily at some frequencies than at others. These resonances largely determine the playing frequency and thus the pitch, and the player in effect chooses the desired resonances by suitable combinations of keys. Also, the saxophone acts as a closed end resonator, and, more simply, a conical pipe. The natural vibrations in the saxophone that cause it to play notes are standing waves. The standing waves in a cone of length L have wavelengths of 2L, L, 2L/3, L/2, 2L/5... in other words 2L/n, where n is a whole number. The wave with wavelength 2L is the fundamental, that with 2L/2 is called the second harmonic, and that with 2L/n the nth harmonic. The frequency equals the wave speed divided by the wavelength, so this longest wave corresponds to the lowest note on the instrument: Ab on a Bb saxophone, Db on an Eb saxophone. For a more complete overview, visit the University of South Wales website on acoustics: https://newt.phys.unsw.edu.au/jw/saxacoustics.html#overview
  5. Recently in my BC Calc class, we've been talking about series and in some cases the application of them. The harmonic series is especially applicable to music: in music, strings of the same material, diameter, and tension whose lengths form a harmonic series produce harmonic tones. Another application of the harmonic series is the Leaning Tire of Lire, a theoretical structure. Suppose that an unlimited identical books are stacked on the edge of a table in such a way that the maximize the overhang. In order to maximize overhang but prevent the structure from collapsing, we can apply the formula for calculating center of mass: c= (x1M1 + x2M2) / (M1+M2). In order to maximize the overhang, we need to stack the books in a way such that their center of gravity remains at x=0. This prevents the weight of the stack from applying a torque to the stack, which would result in an angular acceleration and the toppling of our structure. If we consider the center of mass of the stack with n+1 books, we get the following: The length of the overhang, therefore, can be modeled by the harmonic series, . Theoretically, the harmonic series will balance with an infinite number of books. It takes 31 books for the overhang to be two books long, 227 books for the overhand to be 3 books long, and over 272 million books for the overhang to be 10 books long. Crazy stuff.
  6. That's so cool, that touch screens act like capacitors
  7. Skimpy
  8. Mr. Fullerton recently gave us a hand out explaining electromagnetism and how it directly relates to Einstein's Theory of Special Relativity. According to the theory, length and time are not absolute measures, but can be perceived differently based on the motion of the observer. This can be applied to current in a wire. Take a wire with no current flowing in it. As a whole, the wire is neutral as there are equal numbers of protons and electrons. When current flows through the wire, the electrons flow in a specific direction. The density of positive and negative charges in any section of the wire is the same, however, making the wire still neutral. Imagine a charged observer object moving outside the wire. The charges within the wire experience different motion relative to the charged object, so the separations of protons and electrons differ slightly from the observer's perspective, creating a difference in charge density, leading to a non zero net electrical charge, and therefore a net electric field. The charged observer sees the wire as having a net electric charge; therefore, it experience a magnetic force. It is crazy to think that the charged observer would experience a force simply because of what it perceives in the wire; even though the wire is neutral, it is not neutral to the charged observer. Crazy stuff.
  9. I've never heard of the silver egg illusion before. Very cool!
  10. I never knew that turbo systems pump more air into the cylinders of the car.
  11. I will definitely beat you in Jenga.
  12. That is so cool. I can't begin to imagine all of the complex computer science involved in creating something like that.
  13. I never knew that cruise ships have thrusters. I can how important they are considering how of an impulse they need to deliver in order to keep the boat going in the right direction!
  14. Recently, astronomers discovered a solar system much like ours that could potentially support life. Seven earth-sized planets orbiting nearby star Trappist-1 were found this past week. The solar system is 40 light years away from the Earth. At least three of the seven planets are the right temperature to sustain life. They're rocky and could have oceans. Their orbital periods range from 1 to nearly 13 Earth days. All of the planets are located within a distance from Trappist-1 that is 1/5 the distance from Mercury to our sun. However, Trappist-1 is a relatively cool star, making the temperatures on these 7 planets not too hot despite their close proximity to their sun. This discovery indicates an increased possibility of extraterrestrial life, which is pretty cool. We are still millions of years away from ever being able to travel to this planet, but nevertheless its discovery is exciting.
  15. Last week, I went bowling for the first time in a long time. I noticed that there is a lot of physics in the sport. When rolling the ball, the bowler applies a force to the ball causing it to accelerate and travel with a relatively constant velocity down the lane. The reason that the ball does not decelerate very much at all is because a substance with a very very low coefficient of friction is applied to the surface of the lane, making the force of friction on the ball small, but nonzero. If the force of friction were zero, the ball would not rotate at all. Bowlers also commonly apply a torque to the ball when throwing it down the lane. This causes the ball to gain rotational kinetic energy. The friction of the ball on the lane also causes the ball to move outside-in.