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## The Physics of a parafuso

This is by far one of my favorite tricks to do along with butterfly kick and butterfly twists, (they link up really easily) but a parafuso actually shows how well the human body takes linear momentum and converts it to angular momentum but adding the upward force. The ginga (pronounced like jinga) is the building and wind up guard of this martial art. it has the leg back on one side and the arm back on the other. This basically gives range of motion to throw parts of the body into motion with more anticipation and control. But the first thing you'll notice is the 180 turn before he jumps. This turn causes the initial linear-angular transition as the hips are bent forward. Next he throws his arms into the angle to gain momentum from their mass, and the legs are swung around until either both can land (regular) or the first leg to take off is tucked back and you over turn the kick into a 540. This trick is done 'perfectly' when the middle of the kick can be as far back as if one were lying down, where the transition from linear to angular momentum would be the most efficient, and also where the most height can be reached by the kick itself, allowing the momentum afterwards to carry through to the next motion.

## My "helmet"

In the classroom and around school I know that you mostly know me for my fedora, but on the karate floor i cant wear a hat so, I'm kinda stuck with these curls. Hilariously enough, sensei zak was joking about how my head always comes close to the ground on arials in front of the white belt class, then remarked "no, he just has a helmet for hair." I actually wanted to see that if my head and curls really were springs, what would the spring constant have to be on on giant spring to bounce me back, considering the curls come about an inch and a half off my head, and i mass in at about 70 kg. when just standing on my head. i would have about 700N of force pushing back on my head, which needs to be made up for by the force of the spring. F=kx x=1.5 inches=3.81 cm=.0381 m 700=.0381k my hair would have to have a spring constant of 18372.7 N/m, way over anything we had in labs in physics, let alone made by my hair, or using it as a "helmet" but hey, its funny to for the kids to hear, and it was a fun day doing all those tricks teaching my students (yes, a student can have other students )

## physics surfing

Okay, so in the quest for knowledge of physics i have come up with the worst sport of all time, physics surfing, clicking on physics in stumbleupon and trying to reach the end, gathering as much info as possible. This will never catch on though. So i decided to make a post about the physics OF surfing instead the Physics of surfing is actually kind of cool, relying on fluid resistance (much like that of air resistance) going upward in the circular motion of the wave (or arc motion of the wave) until the surfer's gravitational force matches that of the Frictional force of the water. The speed of the surfer depends on both the speed of the wave and the angle of the surfboard, because as the surfboard angles there is less surface area, and thus less friction between the board and the water, causing the surfer to either speed up, or in worst case scenario, break the surface of the water, or catch the wrong current and wipe out. This is similarly experienced in wake-boarding, para-sailing, and windsurfing, although the upward force to match that of the water, along with the lateral force (supplied by that of the water in surfing) are supplied by different sources leading to a similar effect. i dont know why, but with the variety of land sports and the physics of each, i would think that not all water-board sports would be the same. but from a physics perspective at the surface, they are all EXTREMELY similar.

## physics surfing

Okay, so in the quest for knowledge of physics i have come up with the worst sport of all time, physics surfing, clicking on physics in stumbleupon and trying to reach the end, gathering as much info as possible. This will never catch on though. So i decided to make a post about the physics OF surfing instead the Physics of surfing is actually kind of cool, relying on fluid resistance (much like that of air resistance) going upward in the circular motion of the wave (or arc motion of the wave) until the surfer's gravitational force matches that of the Frictional force of the water. The speed of the surfer depends on both the speed of the wave and the angle of the surfboard, because as the surfboard angles there is less surface area, and thus less friction between the board and the water, causing the surfer to either speed up, or in worst case scenario, break the surface of the water, or catch the wrong current and wipe out. This is similarly experienced in wake-boarding, para-sailing, and windsurfing, although the upward force to match that of the water, along with the lateral force (supplied by that of the water in surfing) are supplied by different sources leading to a similar effect. i dont know why, but with the variety of land sports and the physics of each, i would think that not all water-board sports would be the same. but from a physics perspective at the surface, they are all EXTREMELY similar.

## Skateboarding

Okay, so today i was skateboarding, thinking about blog posts, but also thinking about all the forces and such that go into just doing a few tricks. Such as the kickflip, where the board spins on the lengthwise axis (for those of you not skateboarding people). It needs the physics of the ollie, which is downward force on the tail, force upwards because of the fulcrum of one of the axles, and forward momentum from pushing with the front foot, for an inertial fulcrum that rotates the board up into the air. From there, the rotation is caused by a downward force on the edge of the board, but, the force often isn't so much downward as it is across, similar to how the ollie levels the board not by pushing down, but across. That's the part that blew my mind, most of the forces and tricks using a skateboard are only possible because of the increase in friction from the grip tape, making the entire idea of skateboarding reliant on friction, not just with rolling down a hill and stopping, but every trick involved NEEDS friction to be done. Kinda just something cool i thought of.

## What I've learned from kerbal space program. TOP 5

Okay, so for the last few months in physics we've worked on the kerbal space program, and although my group didn't really accomplish much, i kinda just wanted to finalize a few things that i learned. So there is my top 5 1) Kerbals are easily startled. meaning, these kerbals are astronauts that should have been previously trained and have experienced the forces existing in a spacecraft or spaceplane in the game. clearly this was bypassed as much as the safety measures on my rockets 2) Orbit CAN be achieved, around anything. if you think that you will randomly drift out to space when you launch a rocket, that turned out to be a rare occurrence for me. I often would randomly test out a rocket to see if it was too heavy or light to do anything, and it would drift off, past orbit, and then into orbit of the sun, right near kerbin. 3)Air intake does not work in a vaccuum. and for those of you that think its a no brainer, i went into this with no previous rocket science training besides the universal F=ma and g=9.81m/s2 Therefore, i had no idea that on the alpha version of a game that they could differentiate atmospheres from space, but CLEARLY by the plummeting altitude and increasing velocity of my ship, that would be a 'NO' 4) Kerbal's Mun is really hard to get to if you have no idea what you're doing, but look up a single video and orbit 'slingshots' make a heck of a lot more sense. 5)if all else fails, every physics class can be the fourth of july (with satellites, not kerbals PLEASE)

## Quickie off topic post

Okay, so recently i realized that there is actually physics applied to the way a string orchestra is organized. (minus the woodwinds in there its exactly what im used to) The larger instuments such as cellos and double bass take longer to speak because of the distance between the back of the instrument where thr sound peg produces resonence and the front of the instrument to where it speaks is greater. Therefore they need to be closer to the audience and more on top of the beat than the smaller instruments such as violins and violas. First violins are always in the front because they are almost always the melody of the Piece, thus their sound needs to be mroe forceful and by decreasing the distance between instrument and audience, the sound will be more audible and better balanced between harmony, melody, and background beats. Also, the further back you are, the more on top of the beat you need to be, because in the time it takes for the instrument to speak, then reach the front of the stage could be off by a few thenths of a second. This would end up for a jumbled and badly timed piece. ~sorry, in the orchestra room and definately felt like posting that. [ATTACH=CONFIG]648[/ATTACH]

## Hilarious quote (parkour 2.5)

This one is a more general physics post, but has some applications to parkour. A funny quote that i cant seem to find the source of "speed never killed anyone, its coming to a sudden stop. thats what gets you." thats actually a true statement, because so long as the speed is maintained or gently slowed the risk of injury is very low, but when speed is instantly accelerated to a stop, the impulse of the situation grows (the change in momentum over time increases.) This applies to parkour because no matter what someone does, they need to come to a stop somehow, whether it break bones in the process ro not one needs to come to a stop (or else parkour would be more of falling through roofs than jumping over them.) MAny moves in parkour and general gymnastics are made to dissapate momentum, such as the dive roll (which i made a post about already) or 'catting' a wall. 'catting' is gripping the wall with the edge of the fingers and hand so that while you are temporarily falling from the wall or surface, you can use your feet and arm strength to apply friction and stop before slipping. But at the speed at which the downward fall occurs leaves a very tine balance between apllying friction quick enough and too muych force on the ankles and hands (normal force of friction and the haanging force), or too much speed and slipping altogether. Overall think about it, speed doesnt kill anyone, its sudden application of inerta and force against a surface that does them in.

## Physics of Parkour 2

As with the last one, this post focuses on the disspation of momentum in parkour, but this time, a little but simpler. This one focusses on the move called a dive roll. the move is essential because not only does it dissapate a lot of momentum over a short distance, AND have the abaility to cover large distances but it also allows one to land from a flip that has overspin beyond 90 (preferable beyond 135) degrees. A dive roll is basically a jump into a half flip in which the person lands on their hands, curls their back, abnd rolls out. It decreses the impulse by applying force to a growing surface area and increasing the time of the landing, thus lowering the force applied to the body over the short period of time which would be the landing, but then includes a roll. Its a very fun trick and while ive done it off of small obstacles, a close friend and coworker of mine can do them over 5 ft on hardwood floor from flat ground. if I can get a video of himm i'll post it.

## The Physics of Parkour (1)

Okay, had a lightbulb moment that not many people have gone into the physics of some gymnastics moves and the physics of parkour in general. Hopefully you all know what parkour of freerunning is. Its a hobby and sport in which one tries to get from point A to point B (which can be anywhere from a couple of feet away to a half mile cityscape obstacle course) in the most creative way possible. This can include jumping over buildings, railings benches, or using them to one,'s advantage and finding footholds and cool tricking spots. But the tricks are designed to test the limits of the human body, they can include ten foot straight drops, or fenced over obstacles. Anywho, On to the physics. The first Thing i would like to touch on is large drops and rolls. Larger jumps and drops often include a front flip or trick with them, but more often than not These rolls aren't optional. The first flip off of a drop brings that anglular momentum to roll when the person lands. it seems like it would be harder to land a large drop with a flip, but so long as one doesnt underspin, (overspinning under 45-degrees can be accounted for and is able to work with because of the roll afterwards) the fl;ip helps the transition into the roll after the high drop. Then, when the person lands, the direct downward momentum gets changed into forward momentum through the roll or series of rolls afterwards. This dissapates the kinetic energy that could easily break someone's legs or back when landing. the video from 'fight science' on NTGEO shows more on the physics and goes indepth into the specific force and impulse/time that a person feels doing a fourteen foot drop. skip to 4:30 and watch for about a minute to see the physics behind the madness of dropping beyond human limits

## rainbows in clouds

This is a rare light phenomenon called a 'circumhorizontal arc' which in better terms is a rainbow in the clouds. It occurs when light is refracted and then split into the full spectrum just like that when moisture creates a rainbow after it rains. The slight differentiation in the wavelengths of red to purple light create a different diffration angle for each type of light, thus, the white light seperates into its visible parts: a rainbow. The clouds though, must be very high in the sky, as the rainbow we see after it rains occurs because the sun is on the opposite side of the sky with respect to the rainbow, to form the correct angle (usually 46 degrees) but these rainbows form, high enough int he sky that the correct angle of refraction can occur before the light passes over our heads., at a 22 degree angle and in rare cases with a hazy sky, the entire halo can be formed aroung the sun. This is similar to the rainbows we see in waterfall mist, although much larger scale and MUCH higher up in the sky. Similarly, there is a rare occurence in which the moon is bright enough (or a camera has a high exposure setting) where a waterfall can get the mist at the correct angle to make a moonbow. Also, next time that you can see the moon behind a hazy sky, look closely at its 'halo' of light, in the edges, the haze differcta the light into a rainbow-like arc; called a 'corona'. (moonbow at yosemite) (lunar corona.)

## first quarter in review

Now that the first quarter is coming to a close, i would just like to take a physics and calc review (because most of the class is in calc-bc too, and for those of you who aren't *cough kaila cough* well, your loss. -In physics we did our first formal lab report which turned out to be a lot easier than expected. -We also built catapults, which in review was great and i'm glad that some of them didn't snap the arms from tension. -The Unit that we are currently in- Momentum and Impulse, is our very first alone unit, where we learn on our own, Mr. Fullerton will only come into play every once in a while to say "okay, do you understand this yet, yes-good no-you should." it's bringing independence to our daily lives which I really like. But we will be testing the success of it with the upcoming exam :eek: -In calc, things continue to get more and more complicated while somehow still making sense as we spiral into specific situations then we go back and look at the larger picture only to find we just finished painting the corner and nowhere near the whole thing (similar but less traumatic feeling with physics) -Mr. Muz reviewed integrals with us which brought a little light to Mr Fullerton's "wait 'til Mr. Muz does it and you'll understand much better." so now we do! As said in the last blog post all sciences are connected, and science is connected to math, so I feel that calc holds a special place in my blog to make sense of everything with raw numbers before or as we apply it to real life situations Thanks for being there for the first great quarter you guys, now that we're waist deep and almost a third of the way to APs, time to put it in full steam ahead to confusion and insanity! ~phil dzielski

## XKCD win

Okay, for any of you nerds or science lovers out over there (im on a blog about physics, there better e at least one of you besides me and my sister) you've probably heard about XKCD. FOR THOSE OF YOU THAT DONT KNOW: its the smartest joke site on the net, everything from politics, to math, to physics, to psychology, jokes abound, i HIGHLY suggest you check it out.: http://www.xkcd.com anywho, i found this one comic about the purity of the sciences and how there isnt just psychology, biology, chemistry physics and other things, their all subareas of other sciences. and science itself is just the study of everything. but this one has a hilarious ending: [ATTACH=CONFIG]535[/ATTACH] and this my friends, is why we need MR. Muz to survive physics AND math and U need Mr. Fullerton to survive chem AND physics they apply to each other, or we could survive the school day with a bottle of motrin, your choice :3

## 10th dimension, or 10 dimensions.

another theoretical mind boggling post, if you want to skip my blabbering please watch the video, its fun to watch every single time: okay, so in string theory, the strings cannot exist unless there are 10 dimensions. some believe that these dimensions are micro-dimensions, lying within the smallest depths of the space-time platform described by Einstein. One of the better descriptions of this is in a Ted talk about string theory, (im not going to post it, its 20 minutes and the guy takes forever to get to his point) but basically he says that the dimensions are so small that every time we move they could pass by us on the space-time continuum. Others feel that these 10 dimensions are macro-dimensions, large enough for us to understand and experience even though we cannot see them. This 10th dimensional video is about the macro-dimensions and up to the 4th dimension is basically what my 'finite universes with infinite distances' blog post is about. Theoretical physics does some crazy things, but this idea in which strings may not only exist on a mirco- but also on a macro scale, and could very easily bring together these two theories that they are so small and so large at the same time could, with a little proving and experiment, bring a universal equation for all forces and mass. its pretty cool. the link to the video is right here: http://youtu.be/XjsgoXvnStY these questions are the reasons i love theoretical and quantum physics. thanks for listening to my possibly incoherent blabbering. P.s. theorectical physics is basically based off of repetitive semi-coherent blabbering, only in proof form, so i'm not too far off :3

## Finite universes with infinite distance

Okay, so stumbleupon is the main reason for many of my blog posts as it contains random interesting facts about physics. A mainly accepted theory about are universe is that it is ever expanding and that there are no ends to the space that space is. But another theory is that we live within a finite universe (of which the expanding material is filling slowly) the has no edge. But how can a universe have no edge and still be finite? The method behind this lies in explanations starting from the first dimension. If one could only perceive the 2nd dimension (lines) and we drew a circle for this object to follow, it would be able to pass the starting point multiple times while still feeling as if it was continually going. A finite cycle with no endpoint. therefore we take this into the 3rd dimension that we perceive and we would have to cut through The 4th dimension to make a finite universe with no edges, we just cannot perceive the 4th dimension with human eyes so we do not see the ends, when the ends are really like circles, never ending, just going back to a starting point. But, theoretically, the 4th dimension often is called 'time' but only time in a straight line motion (time travel and parallel universes are the 5th and 6th dimensions respectively.) And according to Einstein gravity especially in large quantities can bend time and space. and since black holes are the largest source of gravity that we know of, could the be the source of the circular pattern and no edged universe that could prove this theory? Or do they exist within an infinitely expanding universe that just spits out matter at another starting point on our infinite plane at a different place? theoretical physics. it messes with minds O_O.

## Cellos and Physics

Okay, so one of last years main subjects (as well as this years) is simple harmonic motion, but thats only a piece of how string instruments and music are created. I personally love the example of cellos (for those of you non string instrument fancy people, giant sit-down violin) since their larger it is much easier to visualize. But what happens is we put rosin (solidified tree sap) on our bows, then pull the bow across the string. By pulling the bow across the string, we make the string act in simple harmonic motion from one end (whether it be the the placed finger or all the way back to the top) down to the bridge. The bridge (a little wooden piece connecting the stings to the body) then transfers the vibrations from the strings' SHM into the body of the instrument. Then the vibrations split in two. one part is thrown across the top of the instrument from the base of the bridge,. Other vibrations are sent through the sound post (a small post in the center of the instrument) down to the back of the bod of the instrument. This causes the air within the instrument to pressurize and depressurize in the compressional wave patterns our ears perceive as sound. So, as a recap, the vibrations go, across the strings, down to the bridge, down the soundpost into the body, pressurize air, then out the F-holes (which IS the technical name for them may i add) To our ears where we hear anything from screeching, to Bach's concertos The way in which we change the notes is either by making a harmonic by putting fingers lightly on the string to create a node in which the vibrations can travel through but creating a halved period on the wave. OR by putting out fingers down which created an end node that generates a different period of wave, in western music the intervals are logarithmic (1, 10, 100, 1000) per octave but in eastern music the intervals are perfect on 5ths (0,5,10,15) per octave, which makes for completely different sounds of music, although both can come out beautifully even though completely different in sound.

## Watching light move

Okay, so, i was using the great and vast world of stumbleupon the other day when i came across this video: [/HTML] they made a camera that takes video so quickly that it can show light moving and the exact actions of light. Its pretty insane. For all of you MIT applicants: this is what you live in the shadow of. the original article is here: www.designboom.com/weblog/cat/16/view/23067/mit-researchers-develop-one-trillion-frame-per-second-camera.html/ there are more videos about the camera. The most amazing part is around 9 minutes where he describes the wierdness of how the camera moving so close to the speed of light that it actually distorts time's order within the video. Basically, the camera warps time slightly by bumping against the speed of light when taking video. Technology is doing some amazing things.

## Karate and physics

Okay, working at a karate school i get huge rants from my boss (and teacher) about how to explain to the kids why we set our hands after we block. From a "tell a kid so it makes enough sense to do it" standpoint we say "because the block is finished and the person can't hit you anymore" from a physics standpoint (and how i taught the teen adult class). The blocking motion in front of your body pivots your pelvis and upper body alone your spine. This is just like a sideways teeter-totter from preschool. now when we set our hands, the hips and shoulders pivot back. so when we bring the hands back, AND punch right afterwards, the force behind the punch isn't just that of the punch, its also the force of the block being set and blocking at the same time. Thus giving more force behind the punch AND more speed to set the hand and get it out of the way before the opponent can grab it and go from distanced hand to hand to grappling.

## Physics of Skateboarding

Okay, so before the hurricane I wan skateboarding and I wondered how I stayed on the board when going through faster and sharper turns. Turns out that there are two sets of forces involved, that of the skateboard on my feet and that of the skateboard to the ground. When you turn on a skateboard, you need to bank both the board and the body to increase the centripetal acceleration (thus centripital force) of me against the board. But banking too much would lead to too much horizontal force against the board when it is acting on the ground, thus making it slip once it passes the maxiumum force of friciton on the ground. [ATTACH=CONFIG]531[/ATTACH]

## "first" post

Hai there everybody! Its me again! I know I took up the legit 'first' post with my ding moment, but this is the "first" post for the assignment xD. I fell in love with physics in the beginning of last year in AP-B so i thought AP-C would be my next step as it is my prospective and currently top possible major. I'm taking some ungodly number of APs which is bound to drop by second quarter but I'm 100% this class wont go . AP-C for me is an outlook into one of the branches of physics through an engineering and application perspective. Also, its about physics :3 and delving into the world of calculus. I just want to get further into my prospective major and I'm probably most nervous about confusing the math between this and Calc BC .

## 'Ding' with vectors.

On friday, we talked about the dot products of vectors. Overall, most of the class wondered why we needed to divide by the vector length (at this time, radical 80) in order to find B-hat. The explanation was in order to make the vector equal to one of its own unit, but having been used to standardized units I and many others still sat there dazed and confused. BUT! once I thought it over, I realized we were just converting the "unit-1's" that the vectors were in into our own unit dictated by the vectors length (making vector B's length a unit). The ding moment specifically was " OH we're making our own set of feet/inches/yards/etc out of the length of vector B" *facepalm* better explained as: vector B becomes your new 'meters' by which you define the dot product of B and A. And the reason we need it to be labelled B-hat is BECAUSE it becomes 1 'length b' which can be converted back to radical-80 "unit-1's" by which the vectors were originally measured. First "ding" moment. 3rd day of school, I think I'm making progress.