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  1. SJamison
    Latest Entry

    So recently I had knee surgery, about four months ago on my right knee. Everything was going well and good until a few days ago. Come to find out I messed up my knee again but wait there's more, this time it was both of them. My right one definitely has another tear in the meniscus and the surgery is scheduled:nurse:.  But, the left knee, however, we were unsure of so i had to get a MRI done. During this I was curious to see how it worked but come to my amazement so was the guy operating it. Despite this I decided to research how it worked. I found out that an MRI machine is just a strong magnetic field ranging from .5-1.5 Tesla. An MRI machine uses this magnetic field to arrange hydrogen atoms in the body along the axis of the machine. once this is done the nuclei produce their own magnetic field that can be detected by a scanner and then form an image.  I thought that this was really cool and the person to come up with an invention of this sort must have been absolutely brilliant. From this machine I hope that it gives me some good news so that I don't need three knee surgeries in a years time frame.  

  2. Our latest unit in gym class is archery and it has me thinking quite a bit about the physics behind a bow and arrow. 

    For example, first of a bow is composed of a frame of some material that can stretch. Next a stein string like material is tied to each end. The tighter the string, the higher the tension. A bow with a higher tension applies a greater force and therefore the impulse delerviered to the arrow is greater, (which of course is change in momentum). Energy is transferred into the arrow which hits a target or deer etc. other factors that come into play include air resistance and the force of gravity. 

    Lastly, there are bows with pulleys that redistribute the force, making it easier to pull back the arrow, but still have a great force applied. The compound bow was invented by a man with the last name Bear. Thanks Bear!

  3. Shadoof
    Latest Entry

    In old times, hunters didn't have guns and cool stuff to help get food. They had to come up with a new and genius way to hunt animals for delicious food. Around 21,000 years ago, some people in the modern day french area came up with the idea of using a lever arm to be able to throw a spear faster, farther, and more accurate. The way in which this device works is that it acts on a lever arm. Since the throwing arm is long more force is applied to the object, effectively multiplying the force put into the spear.

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  4. You may have noticed it’s been a LONG time since I’ve updated this physics education blog.  More likely you haven’t noticed, because it’s been a LONG time since I’ve updated this blog.  This hasn’t been due to a lack of topics to write about, but rather, it’s been a conscious choice to plow full steam ahead on a project that began in June of 2013 and that I’m thrilled to announce is now available, The AP Physics C Companion: Mechanics.  But first, some background.

    Traditional AP Physics C

    As a teacher of calculus based physics (AP Physics C – Mechanics and AP Physics C – Electricity and Magnetism), I’m faced with a very unique challenge in those courses.  I typically enjoy classes of bright, motivated students who are preparing for careers in engineering, science, medicine, and other technically challenging fields.  And I love teaching the content of these courses — the level of technical challenge keeps me motivated, and I love the highly mathematical nature of the course.

    teacher_pointing_at_whiteboard_lg_clr.giIn teaching the class, however, what I found is a very aggressive schedule to fit both courses into the school year, and my students are co-enrolled in calculus (which means they typically need to solve calculus problems in physics before they’ve been introduced to the calculus in their mathematics classes).  Further, teaching in a traditional style, I found that most topics fit fairly well into our 42-minute periods.  Students come in to class, begin with a warm-up question tied to the previous day’s topic, which we spend a few minutes reviewing, then I have time to present a single topic with an example or two each day.  If we don’t take any breaks, and throw in a quiz or test every couple weeks, as well as some fairly straightforward lab activities, we JUST barely get through all of our material in time for the May AP exams.

    What I especially enjoy about this class and this method of teaching, however, is the face-to-face time with the kids during the daily lessons.  Class sizes for AP Physics C is typically small enough that we have a very informal style that is warm and inviting, yet challenging for all.  The students enjoy the class, taking notes from their seats each day, and doing book problems and old AP problems for homework in the evenings.  And our AP scores each year are solid.

    In September of 2011, however, I decided to try something different.  I wanted to get away from the teacher-centric model, as I realized that I was the hardest working person in the classroom.  This contrasted with the best teaching advice I ever received, when our assistant principal and my mentor explained that I should strive to “Look like the laziest teacher in the building while the students are in the classroom, and the hardest working teacher in the building the moment they leave.”  What he meant was students should be doing the work in the classroom, especially as I continuously espoused my belief that physics is something you do, not something you know.  Although the students were doing OK in their passive roles as notetakers, this was a credit to the strength of these students, not my teaching.

    A New AP Physics C Methodology

    Instead, I began to imagine a classroom in which students directed their own learning, building lifelong learning skills that would serve them well outside the narrow discipline of future physics courses.  With the blessings of our administration, I undertook a giant experiment in the classroom.  We went through the year with the goal of having zero teacher lectures.  Instead, I completely “flipped” the classroom.  Students were expected to watch video mini-lessons on topics outside of class, as well as read the textbook and take notes, saving classroom time for group discussions and problem solving, hands-on lab activities, and deeper dives into topics of interest.

    I ended up going back to traditional lectures on two topics — Gauss’s Law and the Biot-Savart Law, but for the most part the class ran independently.  I built up “packets” of assignments, practice problems, labs and activities for each unit, and students worked at their own pace (within reason) through each unit.  Unit exams were given when students said they were ready, with multiple re-take opportunities.  This evolved into a self-paced course, and at the end of the year, I found AP scores were significantly higher than in past years, which in retrospect shouldn’t have been surprising.  Teaching in this more hands-off manner is very uncomfortable, however.  I “feel” like I’m doing a great job when I’m working hard, presenting great lectures, and interacting with the students.  Stepping back and watching the students work, only getting involved to ask the occasional question or provide some basic clarification and support is extremely challenging.  Given the results, though, I tried it again the following year.  Same result!

    student_girl_reading_on_floor_lg_clr.gifThese classes were regularly polled for feedback on the course.  General observations were that many students felt more intimidated and lost at the beginning of the course.  As well, there were several points throughout the year in which the students felt quite frustrated.  Polls at the end of the year, however, indicated students felt very confident in their self-teaching abilities, their ability to work through challenges they initially thought impossible, and their comfort level with their preparation for future studies.  The most common opportunity they identified for improvement — learning how to read the textbook.

    In an effort to address this, I’ve implemented a variety of changes in my classroom.  First off, we take some time at the beginning of the year and again after mid-terms to talk about and practice strategies for reading a technical text.  We also take some time to talk about how to actively use the video lessons and example problems so that study time is efficient and productive.

    The AP Physics C Companion: Mechanics

    AP Physics C Companion: Mechanics

    Finally, I started work on a “companion” text to the AP Physics C curriculum, focused on distilling down the key points from the text and illustrating them with a variety of applications.  Not really a review book (though it could be used in that sense), but rather a cleaned-up version of instructor notes for the course that could be applicable to any calculus-based mechanics course.  A large focus of the book is trading off technical complexity for illustrated application of concepts, including justifications for problem solving steps in the problems themselves, and well-documented problem solutions.

    I’ve been using the notes and draft chapters of this book for several years in my classes, which has allowed me a “test run” of various sections and the opportunity to see what works with students, and what needs further revision.  The final result, I’m excited to say, is now available as “The AP Physics C Companion: Mechanics.”  It will first be available in black and white print editions from APlusPhysics.com and Amazon, as well as a full-color PDF edition on APlusPhysics.com.  Shortly thereafter, print editions (both color and black and white) will be available from any retailer, including Amazon and Barnes and Noble.  Finally, bulk purchases will be available directly from sales@sillybeagle.com (Silly Beagle Productions) at substantial discounts.

    Where’s the E&M Book?

    I’ve already been asked repeatedly if there’s an E&M version planned.  The answer is rather convoluted, however.  The E&M version is half done — the draft is complete as part of my class work and has been for more than a year.  I haven’t typeset it yet, however (probably a 6-12 month project), or worked on the graphics for a few reasons.  First, it is a huge investment of time to do so, which puts other projects on the back burner.  Second, the market for such a book could be pretty small.  As only 27,000 students took the AP Physics C: E&M exam last year, that’s a very limited market to cater to.  Though the book would be appropriate for an introductory calculus-based E&M course, a very significant portion of students taking the E&M exam would have to purchase and use the book in order to recuperate the costs involved in putting out the book (which are substantial).  As most any science author will tell you, there’s not much profit to be made in writing these types of books, and margins are mighty slim.  It’s a labor of love because you want to help students (yours and others).  I’m already pushing the limits of ‘wise decisions’ in marketing a book to the AP-C Mechanics market (53K test takers last year), and hoping it at least breaks even.

    hammock_man_relaxing_hg_clr.gifBefore making any commitments to an E&M version, I want to obtain feedback from the mechanics version — are students and instructors finding it helpful, what is a reasonable percentage of the market to anticipate, would it at least break even, and how is the new format received (fewer pages, larger format and type, color vs. B&W, etc.)  Given all that, I imagine it’s probably likely at some point I’ll get to work on it (after every book I tend to think I’m done, then eventually change my mind and start on another one).  However, it feels good to “fool myself” for awhile and pretend I’m done while I work on updating the APlusPhysics site, continue work on instructional videos, and perhaps get to bed a little earlier in the evenings.

    For now, however, I’m excited to announce the release of The AP Physics C Companion: Mechanics.  Hope you enjoy it as much as I enjoyed putting it together!

    *AP and Advanced Placement Program are registered trademarks of the College Board, which does not sponsor or endorse this product.

    The post New AP Physics C Mechanics Book Release appeared first on Physics In Flux.

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  5. (49 short days until game #1)

    Today was a very eventful day in the baseball world.  Spring training started and Hannah and Derek Jeter announced the birth of their first child.  To celebrate both,  I thought I would break down the physics behind two of Derek Jeter's most iconic defensive plays. 

    The first play, commonly called the "jump-throw" is known across the world by almost any baseball player or fan.  It starts with a sharply hit ground ball towards the hole between Jeter and third base.  Looking at simple kinematics- based relationships, it is a large feat in itself for Jeter to be able to intercept that ball by moving as far and as fast as he did.  Next, he calculated the exact flight of the ball as it hopped into his glove, and then with the full momentum of his body taking him away from first base, unleashed a powerful, incredibly accurate throw that beat the runner and ended the inning.  Critics say that the only reason that play was made was because Jeter didn't have the speed to get to balls hit away from him, but nobody can deny the fact that the throw, made perfectly, despite the fact he was traveling at a constant speed away from his target and being accelerated back to earth by gravity, is one of the greatest of all time.

    Another iconic Jeter play, made in a pivotal playoff game against the Oakland A's shows just how good of a physicist Jeter was.  The play began as a defensive error by the right fielder.  He made an awful throw trying to get the tying run out at the plate.  He missed the 1st baseman who was supposed to relay the throw home, and instead sent it sailing into the grass by the 1st base dugout.  All of the sudden, Derek Jeter came streaking across the field, and on a full sprint fielded and backhand flipped the ball to the cathcer, Jorge Posada, who nailed Giambi with a quick swipe tag to preserve a 1-0 Yankees lead.  The physics come in when Jeter released the ball.  Travelling at over 15 mph, Jeter knew exactly what vertical and horizontal angle  to launch the ball at in order for it to be delivered to Posada to enable a smooth tag.  In the video, one can clearly see how the ball seems to curve as it is being delivered to Posada.  This is because the ball is moving in all 3 directions at once.  It is moving forward with the force of Jeter's "push", sideways with the constant velocity supplied by the sprinting body, and downwards due to gravity.  By correctly judging all three of these factors and many more, Derek Jeter was once again able to make himself into baseball legend with the flash of his glove and the flick of his wrist.

    Here is a video of some of Jeter's best defensive plays.  It starts off with The Flip and his Jump-throw is at 2:44.

     

  6. As a saxophone player, I have always wondered how exactly sound waves work and why some notes sound good together while others don't. For example, when notes that are a half step apart are played simultaneously, "wobbles" are produced. If two sound waves interfere when they have frequencies that are not identical but very close, there is a resulting modulation in amplitude. When the waves interfere constructively, we say that there is a beat. The number of beats per second is known as the beat frequency, which is simply the absolute value of the difference in the frequencies of the two pitches. From a music theory standpoint, intervals can be referred to as consonances or dissonances. Consonances occur when tones of different frequencies are played simultaneously and sound pleasing together. Dissonances occur when tones of different frequencies are played simultaneously and sound displeasing together. According to a lecture by Professor Steven Errede from the University of Illinois, the Greek scholar Pythagoras studied consonance and dissonance using a device known as a monochord, a one stringed instrument with a movable bridge, which divides, "the string of length L into two segments, x and L–x. Thus, the two string segments can have any desired ratio, R = x/(L–x). When the monochord is played, both string segments vibrate simultaneously. Since the two segments of the string have a common tension, T, and the mass per unit length, mu = M/L is the same on both sides of the string, then the speed of propagation of waves on each of the two segments of the string is the same..." Basically, the ratio of the lengths of the two string segments is also the ratio of the two frequencies. Consonance occurs when the lengths of the string segments are in unique integer ratios. To learn more about the physics of consonances and dissonances, read his lecture here: https://courses.physics.illinois.edu/phys406/lecture_notes/p406pom_lecture_notes/p406pom_lect8.pdf.

  7. One of the most well known track and field events is the long jump. This event is where an athlete sprints as fast as they can toward a line then jump into a sand pit. Several simple kinematic concepts are displayed in this event. Firstly the distance traveled by an object is proportional to the velocity of an object. This translates to the long jump in that the faster the person is moving as they approach the point where they have to jump, the farther they will travel. Also the length of the jump will be determined by the angle the jumper makes with respect to the ground. The ideal angle for this is 45 degrees, because this produces an ideal balance between velocity going in the x-direction and the y-direction. Therefore any good long jumper will have both good spped as they approach their jump as well as the skill to propel themselves at a 45 degree angle to the ground in order to produce the maximal distance out of their jump.

  8. In the spirit of the new resident evil game coming out very soon, it should be interesting to find out how many characters should have died in the previous game in a helicopter crash. Throughout Resident evil 6, the are a few helicopter crashes, and in the usual horror game scare tactic, everyone but the main characters die in these crashes. But should your characters have lived? There is an average of 1.44 fatalities per hundred thousand hours flown in a helicopter, and you can probably make a safe guess that if your helicopter crashes, you're at much higher risk for dying. Although there are countless factors that play into how a helicopter crash will turn out, lets just break it down to its simplest form, how high up would a helicopter fall from, and how much does a helicopter weigh? An average cruising height for a helicopter is around 2000ft or 609.6 meters, and an average helicopter weighs about 10000 pounds or 4535.924 kilograms. So, with those estimates, a helicopter would hit the ground with roughly a force of 2765099.27 newtons, and while it is definitely difficult to say how much force it takes to kill a person, it is most likely safe to say that this much force spread out across your entire body as well as the environment around you is lily enough to kill you. So based on this, things aren't looking too good for our heroes Leon and Helana, especially considering even if they do somehow miraculously survive the initial impact, they would still have to immediately begin fighting zombies, and with those odds, chances of survival are looking pretty poor. So, is it possible to survive a helicopter crash? Yes. Is it likely? no. Falling to the ground in a 10,000 pound box of death is generally not very good for your health and should be avoided at all costs if possible. 

     

  9. In Battlefront, the main infantry weapon is a gun that fires lasers. Though it would be amazing, this will most likely never be a reality because of a few properties of light: refraction and scattering. Light can bend, and will in foggy or rainy conditions. Also, it will disperse as it travels, reducing the intensity. Another reason why it is impractical is the energy requirements for a laser beam that can kill. To create a laser beam that is strong enough to kill, 24 Kg of batteries must be used. This is extremely impractical compared to lighter magazines which can hold a large amount of bullets.  Light also has a velocity that is larger than escape velocity, meaning that it will not drop and will just shoot off into space for all eternity. Until light can be harnessed more efficiently or a more compact source of energy can be found, i do not believe that we will be seeing laser rifles anytime in the near future.

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  10. Swings are found in children's playground and are very fun and enjoyable. They work just like a pendulum. A swing converts potential energy into kinetic energy as you swing. When you first get on the swing and take step back as far as you can to get the best swing you build up potential energy. When you pull your feet up and begin to swing your potential energy is converted into kinetic energy.  When you reach the the maximum height form swinging your potential energy is built up and again is lost when you swing back down. By swinging higher you build more potential energy and swinging faster makes more kinetic energy. So remember that the next time you start swinging all's your doing is converting energy. 

  11. I am a black belt and I always enjoyed the physics behind karate as they are often more complicated than most people first think.  When two people line up to fight, they both bring a certain amount of kinetic energy to the fight.  This is determined by their weight, height, muscle strength and also their physical health.  The main principle behind karate is to use your body to channel this energy and make maximum use of it.  It also focuses on how you can take away from your opponents with smart blocking a defense maneuvers.  We can often base the power of these punches on F=ma^2.  Since our mass is going to be constant it is important to find ways to increase our acceleration of the punch to generate more force.  When you combine this with the ability to channel and make most of your kinetic energy, you give yourself a huge advantage in any fighting situation.   

  12. The kid's movie UP, while serving it's purpose as a kid's movie, isn't exactly known for being accurate in the physics department. In the movie, an entire house is lifted up by nothing more than balloons. This iconic scene is pretty, but is it probable? Discovery channel's Mythbusters decided to test it harnessing a small girl into a ton of balloons, and seeing how many it would take to lift her. They estimated about 2000 fully inflated helium balloons would be enough to lift the young girl, but with a sandbag dummy they found they would need upwards of 3500 balloons. After tying up all 3500 balloons to the harness, she was lifted into the air purely by the power of balloons. If it took 3500 balloons to lift a small girl, it would likely take millions of balloons to lift a house off of it's foundation and then into the air.

    http://www.discovery.com/tv-shows/mythbusters/videos/balloon-girl-minimyth/

  13. fiber optic cables are used to send messages at high speeds and at great distances. There exists a fiber optic cable traveling from New Jersey to England! fiber optic cables work by sending pulsing light through a specific material. since light is the fastest thing in the universe, fiber optic cables are the fastest form of communication in the known universe. as you know, light travels at different speeds when its inside of a different median. the ratio of the speed of light in air to the speed inside of the material is known as the index of refraction. a higher index of refraction means that light moves slower through the material. the core of a fiber optic cable has a much higher index of refraction than the outer layer. when light travels through the core, it is reflected off the boundary between the materials. this allows the cables to bend and not lose light. 

     

  14. While it might not be a major pastime for me, I enjoy learning about magic. Not of the satanic ritual variety, but of the slight of hand, stage/street variety. Sometimes I like to use this to harass my friends with impossible tricks, other times I just do it to practice some fine technical skills. In this case, namely how to throw playing cards.

    If you have a deck, go grab it right now, and try to throw a card. Watch, as it flops to the ground like a piece of paper. Now, grab it by the corner, and try throwing it like a frisbee. Suddenly, the card will move in a straight line or arc, and, depending on what you're throwing it at, lodge itself in its target. Why does this change in motion change the outcome of the throw? To explain it simply, by spinning the card, the angular momentum of the card prevents it from being easily rotated in another direction. Combine it with the low air resistance that you create on the card's edge when throwing it in such a manner, and the air resistance prevents the card from actually fluttering down like it would if not spinning.

    While I'm on the topic, let me mention that, while it could stick in the right target, a playing card CANNOT be used as a weapon. Due to its relatively low mass, it would lack the sufficient energy necessary to cause more than a small paper cut to the human body. If you don't want to believe me, however, know that this myth was tested by the MythBusters, and a card launched at 150 mph by a machine didn't have enough energy to cause more than said paper cut.

  15. prettybird
    Latest Entry

    Last night, I went out and saw the movie Split. I was slightly intrigued by the reviews, and it was said to have a really surprising ending, so I put aside some of my personal opinions on the topic of choice and watched it. 

    It was a very interesting movie to say the least, and if you're planning on watching the movie, I would stop reading here, because in order to get into some physics I have to spoil the ending, which is entirely the best part.

    Okay, now that you're sure you want to continue, the movie is about a man with 23 distinct personalities inside him, which all take control at different times. While one, Barry, is in control, he kidnaps three girls. Three of the personalities (Barry, Ms. Patricia, Hedwig) believe in a figure called the Beast. The spectators find out that the Beast is not a figment of their imaginations, but actually a 24th personality that has super powers. Just by switching to this personality, the man's body becomes impenetrable and extremely strong.

    The only surviving girl, Casey, tries to shoot him with a shotgun and the bullet essentially bounces right off. That's where the physics comes in. How much force would a regular shotgun shell impart, and how strong would this man's skin have to be?

    A 1 oz. shotgun slug leaves the shotgun at 1800 fps, or about 550 m/s. This slug would weigh about .03 kg, giving it a momentum of 16.5 kg m/s. Assuming that the bullet was only in contact with his skin for .001 seconds, and it was a perfectly elastic collision, the force imparted onto his skin would be 16500 N. The only metal I could find info on was steel, and it can withstand 40 kN, meaning that his skin could withstand atleast half the force steel can.

  16. eclark
    Latest Entry

    kix-science-magic-bag31.jpg 

    The answer is no. This image seems too good to be true, but this experiment is completely possible. The reason the pencils are able to go through the plastic bag without leaking is because of the material of the Ziploc bag. The plastic baggie is made up of polymers which are long chains of molecules that are flexible. When the pencil is pokes through the bag, it slips in between the chain of molecules. They then make a seal around the pencil which ensures that water will not leak out. 

  17. jcstack6
    Latest Entry

    Many people think time travel is absolutely ludicrous, but one has to consider what kind of time travel they are referring to. To travel back in time is ludicrous, because if this were ever to become possible, there would have been discovered evidence of time travelers from the future that came to our time. Time travel according to Einstein's theory of Relativity, however, is not only plausible, but true. According to Einstein, as one increases the speed at which they travel, the rate of change of time is less for them than it is for an outside observer. Based on this idea, one can travel in time by going at incredibly high speeds. By traveling at high speeds, a person will age slower than an outside observer, showing the person traveling so quickly will have, in essence, time traveled forward. So time travel backward will, most likely, never exist, but time travel forward, if great enough speeds are attainable, is fairly simple to accomplish. 

  18. Super Mario Galaxy's hub world is known as the Comet Observatory. In its center is what a character describes as a "ball of flame" called the Beacon which powers the whole observatory. This beacon starts off small, but as the player collects Grand Stars, the beacon grows in size and changes color. This beacon changes color from burgundy, to orange, to yellow, green, greenish-blue, blue, and turquoise. I'm sure from this description your immediate thought is "star". However, if this beacon was really a star, the heat it would be releasing would be catastrophic for anyone nearby. Stars' gravitational pulls are powerful enough to control the movement of planets, let alone the effects it should have on Mario and the Observatory. Mario should be lucky he hasn't melted yet. Most 3d Mario games have been about collecting stars, but this is nowhere near the same thing.

  19. jwdiehl88
    Latest Entry

    The last time I was on a airplane was when I was traveling to Florida for vacation.  I wondered how almost 200 people and the mass of the plane didn't weigh the plane down.  The forces on the airplane is at equilibrium when the airplane reaches at a certain altitude.  Additional when the airplane reaches at a constant velocity therefore the forces on it all must be balanced.  This means that the lift force (L) generated by the airplane wings must equal the airplane weight (W), and the thrust force (T) generated by the airplane engines must equal the drag force (D) caused by air resistance.  The airplanes wings and the fins in the back of the air plane, cuts down on drag force and increases the lift of force when the plane is increases its altitude.  The wings and fins makes the airplane aerodynamic letting the airplane go faster when its flying in the air.  

     

     

     

    forces acting on plane during level flight

     

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    Physics can be applied to every aspect of swimming. Before even entering the water, swimmers model free fall and angled projectile motion as they dive off the starting blocks. U.S. Masters Swimming states that diving at a 45 degree angle maximizes the speed and distance of the dive. Competition suit brands, such as Speedo and Arena, have to be knowledgeable about the physics of water resistance in order to produce their extremely tight and specially-designed "Fastskins" that are known for helping swimmers achieve best times by strategically compressing their bodies to maximize speed and to minimize water resistance. However, the best examples of physics found in swimming are found when applying Newton's 1st, 2nd, and 3rd laws to the sport.

    Newton's 1st Law states that an object at rest tends to stay at rest and an object in motion tends to stay in motion, at constant velocity and in a straight line, unless acted upon by a net force. It is also known as the Law of Inertia. When swimmers dive into the water, they hold themselves still in a horizontal streamline position for a few moments before starting their kick. Water resistance acts as the net force, which quickly begins to slow swimmers in streamline position. This is when they know to start kicking because, otherwise, the water will end up stopping them. Furthermore, taller and bigger swimmers have greater inertia, so their speed off the block and speed of flip turns are naturally slower. Nevertheless, larger swimmers are often stronger and therefore able to produce enough of a force to dive and turn quickly.

    Moving on, Newton's 2nd Law says that the net force on an objects is equal to its mass times its acceleration. The more force a swimmer can apply, the faster he/she will go. It is common, especially in longer events, to see swimmers start out strong, then slow down and start to look tired, and finally speed up at the end for a strong finish. As swimmers get tired, they begin to produce less force, thereby beginning to decelerate. Towards the end of a race, knowing they are in the home stretch and are going to be able to live to finish the event, swimmers muster enough force to accelerate. During practice, a common set is one involving descending times, which exhausts swimmers, since they have to increase the force they are applying to be able to accelerate.

    Finally, Newton's 3rd Law states that all forces come in pairs that are equal in magnitude and opposite in direction. It is commonly said as "for every action, there is an equal and opposite reaction." This law is the most obvious to observe when watching a swimmer. As the hand and arm push the water backwards, the water pushes forwards with a force that is of equal magnitude. This motion keeps the swimmer afloat and allows him or her to move forward in the water. Every stroke involves the swimmer pulling down and back in order to move up and forward.

    Clearly, physics is exemplified everywhere in the sport of swimming. Physics explains why certain stroke techniques are more effective and why some swimmers are faster than others. Even Michael Phelps' success can be credited to his expertise at applying Newton's first three laws to his sport. After reading this, maybe we will see you in Tokyo 2020 with the other great physicists who call themselves the USA Olympic Swim Team!

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    nwaddington
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    My name is Nicole Waddington, as you probably figured out already. This fall I am on the Varsity Tennis team, but normally, I am a coxswain for Pittsford Crew on the varsity girls team. Now, you are probably asking yourself one of two questions. 1) What is a coxswain? or 2) Isn't that the person that yells "Row!" and sits in the boat? Answer to question #1: A coxswain is in charge of steering the boat, motivating the rowers, and a multitude of other things that you can probably find on Wikipedia. Answer to question #2: Kinda, coxswains don't just yell "Row"...unless you want to boat to move. But, our job can best be described as a person who corrects technique and steers the boat. I look forward to exploring the physics of rowing in later blog posts. I also have been playing the violin for 11 years. As far as careers, I have no clue what I want to do. I am taking physics because I really enjoyed AP Physics 1, have already taken AP Bio, and didn't want to take AP Chem. Physics was the first class that I took in the high school that truly challenged me and didn't come naturally which was refreshing. I'm really excited about challenging myself in this class, and also the freedom and independence this class has. Things I am nervous about this year are the difficulty of the content and heavy workload. 

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    Last Tuesday marked the first day of Physics C. After a long summer vacation and countless times emailing my counselor to either add or drop Physics C, I finally made up my mind to officially take Physics C. But before I get ahead of myself I want to let you know about my interests. I've been cheerleading all my life and I played softball for 8 years. I love watching Space Documentaries and even though science was never my strongest subject I thought it was always interesting so I decided to challenge myself. I'm aspiring to become an architect and hope to be attending Hampton University next fall. I've always been interested in engineering and how/why things work. I've decided to take Physics C because I enjoyed AP Physics 1 and this is the only science that I can apply to everyday life. After taking Physics 1 most of my conversations became Physics based so why not take Physics C. Plus Chemistry and Biology isn't really my thing. I hope to solidify what I learned last year but also expand my knowledge. I'm excited to challenge myself and learn how efficiently do all the work I need to do. However, I'm somewhat anxious for the work load and if I fall behind the class will crush me. But whatever the case may be I bet this will be the best class I have ever taken.

     

  21. If someone asks why physics is so important, tell them that the world just wouldn't work without it. Not the way we know it at least. As this is my final post of the year, I thought it'd be a cool idea to talk about what the world would be like if certain parts of physics didn't exist. In a previous post, I discussed the difficulty that would come with living in a world without friction, and I also mentioned how without electrostatic force, objects would phase right through each other. It would also mean current electricity would not exist, but what would that matter if we couldn't even use it. If gravity didn't exist, objects would keep moving until they hit something, and everything in space would just drift endlessly in one direction. Which means the earth could potentially drift into another planet or a star, which wouldn't be good. Without magnets, we'd have to find different ways to generate electricity or make power, and compasses would have never been invented, so navigation wouldn't be as easy. So yeah, physics is pretty important, unless you prefer a world that doesn't work. It's what makes our world possible.

  22. Phyzx

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    L8on
    Latest Entry

    I'm a big fan of Lego. I wouldn't quite call myself an enthusiast, but I do enjoy a good build every once in a while. I remember when I was little I would always try to build these massive structures and would wonder why they would fall apart. Now I see that It's because of my awful engineering. I would create an immaculate creation with weak pivot points, allowing its natural torque to attack all of the little points I left unguarded, until eventually it would crumble. Or worse yet snap, sending Lego pieces everywhere. The Lego pieces will have fought so hard to remain in place, and once the connection is severed, all of that built up energy goes directly into sending little bricks flying all over the place for you to find months later when you're cleaning behind the couch even though you know for a fact that the Legos never actually left you room and how did they even end up down here... Anyway, here's a Lego particle accelerator...

     

     

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