For my final trick, a blog post about blog posts! The assignment of blog posts, 10 a quarter for four quarters, has been a great way to make us think. It seems fitting to reflect on the blog post process itself with this fortieth post. I really think this is a good idea, whenever I sit down to do a post I enjoy the creativity involved, and reflecting on what I've learned makes me appreciate the scope of the class all the more. I definitely recommend that the blog posts remain as an assignmen
Physics is everywhere, all of the time. This seems cliche but I really am beginning to grasp that, as this year draws to a close. No matter what I do, every single day I make connections to the concepts from the classroom and life. I don't try to, but that is what taking physics does to you. It alters your perspective eternally, as things that simply happened before now hold within them staggering amounts of math and headache inducing levels of thought. At any time, a baseball in flight can
I completely failed to mention something I found fascinating in earlier posts, and I believe t deserves its own blog post. The amount of fuel needed to break orbit compared to that needed to maneuver in space is staggering, nearly all our fuel and stages are dedicated to breaking Kerbin's hold. I now realize that as silly as NASA's launches looked to me as a child, with their massive fuel tanks and enormous engines, that grvity his simply that strong. It takes a remarkable amount of fuel to b
Our team landed on Minmus during this project, and other teams landed on Duna and Mun. All of these landings and moonwalks have me thinking about the future of space exploration for humans. For example, I have heard a lot of speculation about a manned mission to Mars recently. There are even some talking of colonizing. It was watching the Kerbals jump so high on Minmus that I realized I will never buy into that theory. Mars' gravity is less than half of earth's, at 3.711 m/s. I cannot beli
Our team in the KSP challenge, Brazanah Inc., won the water bottle rocket challenge this year. This is the second straight year I have participated, and have gained several insights through the process. The first main thing is the value of a parachute, and the power of drag forces. A simple parachute turned a modest rocket that did not go very high into one that lasted 5.85 second in the air, all through air resistance. Our parachute was only a few feet in diameter but the rocket slowed to a
Once we achieved orbit around the sun, I first encountered orbital nodes. These nodes are a fairly simple notion, as relative to a plane of reference there are two points of intersection with that plane. At one, you are crossing from underneath and are ascending, hence the name ascending node. The descending node is where you cross below the plane. While attempting to encounter a planet's gravitational field, we attempted to make our orbital nodes as small as possible, getting them to 0.1 deg
Space Planes! I only recently began experimenting with the space plane features of KSP, but they offer a wealth of information about drag and air resistance. The steering of these planes is so sensitive, that you really see how rudders and pitching affect flight. Also, placing aerodynamic caps on engines rather than leaving them flat noticeably alters acceleration and top speed capabilities of a plane. Trying to build a plane is also complex, as you have to consider how much wight the wheels
Here are the three concepts that I believe I will remember the most from the past year as I go on into life.
1) Momentum and Impulse: I cannot express how often as I watch sports or any kind of everyday movement I am reminded of momentum. Now, when I watch football and see a seemingly big hit, I do not react the same way if I see that the hit was delivered over a longer time, as I would expect, the players often walk away unscathed. Pool is another example, as it is often the textbook case
There is so much to talk about regarding our final project of the year, using the game Kerbal Space Program to explore interplanetary physics. At first, I had no idea how the game could actually teach us about physics. Then, we tried to go into orbit. The accurate depiction of momentum as you try to lock on to a location with S.A.S only to have your rocket oscillate as it slowly loses its angular momentum is a nerve racking and accurate simulation. In a less obvious fashion, learning when to ma
Well, with one more day to go, I would like to attempt to capture a year's worth of memories in a few short words. I have never thought so hard, been so frustrated, or studied so much in my life as I did for Physics C. Despite all that, or maybe even because of it, I wouldn't trade the experience for anything and given the opportunity to do so I would take the class again in a heartbeat. Having a class that forced me to struggle to understand the base concepts, to work just to establish a foot
1) Right Hand Rules. Know the various forms and applications of these rules, they are vital to figuring out how to approach many problems.
2) Ampere's and Biot Savart's laws: These two laws enable you to attack a variety of problems with a variety of givens and be flexible in your problem solving.
3)Don't forget electricity: From what I've seen, the tough problems like to bring in electric fields and other topics from electricity to change things up and make you think. Stay fresh on electr
The right hand rules are infamous. They lead to thousands of physics students nearly tying their hands int knots trying to determine the direction of magnetic fields and magnetic forces. Yet if we can look past that, they are quite remarkable. The idea that someone could find a relationship and develop conventions that enable us to figure out something as abstract as magnetism with our fingers is incredible. The elegance and ingenuity of physicists never ceases to amaze.
There is a very odd and powerful phenomenon in physics. It happens all the time, different scenarios are often expressed with very similar equations. It isn't just Gauss' law working for electric fields and magnetism; the equations for force due to gravity and electric force are strikingly similar, just to name another. This is the beauty of our universe, the same patterns and relationships pop up in seemingly disparate fields of study, another indication that there is some unifying revelatio
The scientists at CERN in Switzerland have apparently seen a rare tau neutrino for only the third time. These subatomic particles have been some of the most elusive to observe for scientists. This finding is critical, as the more we find out about subatomic particles the more we are able to improve our understanding of particle physics and begin to understand our universe. There is a good article summing up the sighting of the tau neutrino here:
While procrastinating instead of doing blog posts, I stumbled across a neat article about something we have been studying. Apparently bees may be using the electric charge and fields they build up while in motion to communicate with one another. This is a very cool concept and if accurate may hopefully enable us to communicate with these animals through induced electric fields. Here is the full article link
The final segment of a study of the physics behind these awesome books will discuss theoretical physics and magical dimensions! In the novels, there exist other planes of reality, such as the magical plane of the Nevernever, and several other dimensions such as the one inhabited by Bob, the spirit. There are also things called Outsiders which are said to come from outside of reality. All of these coexisting planes of existence are similar to several theories of theoretical physics such as stri
One more time, lets examine the physics of the Dresden Files by Jim Butcher. Again, tiny, non plot related spoilers ahead. There are ley lines in the novels, which are essentially underground currents of untapped magic. At places where many of these lines intersect are places with some form of magical significance in the series. This demonstrates Kirchhoff's Current Law, or the Junction Rule. All of the magical current flowing into these junctions is conserved and converges into one, much s
Here is another exploration of the science behind Jim Butcher's popular Dresden Files books. Harry Dresden has a magical shield bracelet, which obeys several concepts of physics rather well. Caution, tiny spoilers ahead. At first, Harry's bracelet enables him to block incoming kinetic energy only, which causes him some problems when exposed to heat. He later expands it to also block heat energy, light and sound as well. The fact that each type of energy needs to be addressed separately, combin
The wonderful series of books by Jim Butcher, the Dresden Files, has an awful lot of physics in many of the magical activities that occur. This is the first of several examinations of the science behind the magic, about Harry Dresden's magic rings. These rings store up kinetic energy slowly over time, and he can unleash it all at once on the bad guys. Lets say every time he moves his arm, one ring picks up just 2 joules of energy. Lets also say that he moves his arm 5,000 times in one day. T
Since it seems so popular to do, here is my take on last quarter. It was dominated by independent units for circuits and magnetism, which brought about some interesting revelations. First, read the book! I didn't do that for circuits, and it made understanding the theory behind all of the material very difficult. I actually used the book on the magnetism unit, and it made a huge difference in understanding the origins of Biot Savart's and Ampere's laws. Also, I need to learn to budget my time
I have long feared the start of Electricity and Magnetism in Physics C, and following the introduction to this semester with a hard unit on E fields and forces, I know that this will be as hard as I thought. I didn't realize that it would be fun however, as I am finding myself enjoying the new elements of electricity such as Gauss' law and the fact that the calculus isn't as bad as I envisioned. There is still a long way to go but hopefully E and M won't be the nightmare I envisioned on day on
What is the Earth's angular momentum? Since L = Iw, we need to know the Earth's moment of inertia and angular momentum. For moment of inertia I will assume Earth is a solid sphere with I = (2/5)MR^2 or (2/5)(6x10^24)(6.3x10^6)^2. This comes out to I = roughly 9.53x10^37. w = (2 pi)/T, and the earth's period is 86400 seconds, so the earths angular velocity is 7.27x10^-5. So, L = Iw = (9.53x10^37)(7.27x10^-5) = 6.93x10^33 (kg*m^2)/s
Hockey is back, so I decided to calculate the max speed a skater can take around a level circular turn on ice with a radius of 20 meters using the algorithm v = radical(urg). With the coefficient of kinetic friction between the skates and the ice being approximately .15, the max speed is radical(.15*20*9.8) or 5.42 m/s.
The times square ball is dropped from a height of 43 m every year at the start of the new year. However, I feel the ball drop should be timed so the ball lands at the turn from one year to the next. Thanks to kinematics, we know the time it takes the ball to fall (neglecting air resistance) is = radical ((2h)/g), or radical ((2*43)/9.8). This means the ball should drop 2.962 seconds prior to midnight to land at the start of the new year. Happy 2013 everybody.
We just finished all of Mechanics for AP physics C, and I want to reflect on the highs and lows of the semester. I most enjoyed learning about rotational motion, specifically angular momentum, as it was so unlike anything from last year. Finally learning to deal with rolling objects felt like a real step forward from last year. I found oscillation to be the most challenging unit, and cross products to be the most confusing new concept. I really enjoyed independent units and hope we do anothe
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