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Showing content with the highest reputation since 11/14/2010 in all areas

  1. 3 points
    Last weekend I crossed the border into Toronto, Canada for a "girls weekend" with my mom and sister. Our main purpose of going there was for a yoga convention for all the yogies of the world. While at this convention, we of course experienced tons of physics! When doing different yoga poses, we experienced the great phenomenon-gravity- at work. When "ohming" or saying "namaste" we experienced sound waves, and the vibration they produced so that we could here them. But when we weren't doing yoga, we somehow still experienced physics! By dropping tons of money at the 3-story mall, The Eaton Centre, we experienced the force that our heavy shopping bags created on our arms. When taking the elevator to a new floor of designer stores, we experienced physics there and how we felt heavier when going up, but lighter when going down due to acceleration. We lastly saw physics when we hit the pool/hot tub in our wonderful hotel. The jets pushed water out creating different waves or bubbles. We also created waves by jumping into the pool. Depending on the type of jump or how hard it was, the amplitude changed all the while carrying the energy we put forth by jumping in. This weekend adventure was full of physics just like everything else!
  2. 2 points
    I played dodgeball too!
  3. 2 points
    The reason why you get shocked more in the winter is because everyone has their heaters on which draws the moisture out of the air which causes the charges to build up and cling to us more since there is less moisture in the air.
  4. 2 points
    ...(But probably not.) In light of the holiday season, I bring to you a Christmas-themed blog post, with a pinch of love and some hints of gravitation. I came home from school today and stepped into the living room, astutely noticing that the Christmas tree had fallen. Obviously, the first thing that ran through my mind was that gravity did this. I mean, gravity's everywhere - it's a pretty likely culprit. You may or may not notice the lamp just above where the tree fell, but I believe it to be of great importance in this investigation. I have deduced that, at any time from 10:00 AM to 2:00 PM on Tuesday, December 16, the gravitational attraction between the tree and lamp created a gravitational orbit that forced the tree out of its holder, and onto the cold ground. Let's take a look. First off, the tree had to begin in static equilibrium - it was still at first. Due to Newton's first law, an outside force had to act upon this tree, and I do believe that the placement of the lamp near this tree provided an IMMENSE GRAVITATIONAL FORCE. So let's dive in. We know that the magnitude of this force is given by GMm/r^2, where G is a constant, M is the tree, m is the lamp, and r is the distance between the two. G = 6.67E-11 Nm^2/kg^2, we know this. The average mass in kilograms for a Christmas tree is about 70 pounds at this height of tree, or 31.75 kg. The mass of the lamp is about 8 pounds, or 3.63 kg. I can already see this force is about to be massive. And the distance between the center of mass of the tree and lamp? About 5.5 feet, or 1.68 meters. Time to calculate. F = [(6.67E-11 Nm^2/kg^2)(31.75 kg)(3.63kg)]/((1.68m)^2) Therefore, the force due to gravity is a whopping 2.72 NANONEWTONS. This incredibly large force undoubtedly caused the displacement of the tree; therefore, gravity ruined Christmas. You may be subconsciously pointing out the holes in my story, like how did a gravitational orbit just occur if the lamp was there the whole time, or perhaps just pointing out the fact that two objects on Earth will likely only apply negligible forces to each other. Fair enough, but keep in mind that there is absolutely no other worldly explanation for this phenomenon. So it's either gravity, or ghosts. You decide. Or maybe the cat just knocked it over.
  5. 2 points
    Physics is involved in pretty much everything in life. Throughout my school day I experience all kinds of physics. First period I have Italian where I sit down (along with the rest of my classes) and I am applying a force to the chair and the chair is applying a force to me because of Newtons third law. Second period when I get my math test score back I hit my head against the desk which is also applying a force to the desk and the desk applies one right back. Third period is art class where I gravity is pushing my eyelids down while I struggle to stay awake. Fourth period is APUSH which could be compared to a black hole. Black holes have tons to do with physics. A black hole is a point in space with so much gravity that not even light can escape and that is most definitely APUSH... Fifth and 6th periods are the best of the day because I do not have classes these periods so I can do my homework. Seventh period is English where I push down on my pencil and it leaves a mark on the many papers I have to write. Gravity also pushes down on that pencil. Eighth period could be the first period of a double for physics or if I am lucky its gym. In gym there is so much physics. A ball is thrown and is a projectile motion. Gravity acts on the ball at all times. If were running in gym we push down on the ground with our legs and the ground pushes us back allowing us to run. And then ninth period, well there is too much physics in a physics class to list. Tons of gravity throughout the day and tons of newtons laws. Crazy..
  6. 2 points
    So if you haven't heard, a rocket that was supposed to bring supplies to the International Space Station (ISS) exploded on October 28. Here's a short article and video talking about it: http://www.wired.com/2014/10/antares-rocket-explosion/. Obviously, this kind of sucks. The rocket cost about $200 million and now most of the supplies won't make it to the ISS. However, explosions are still really fun to watch, especially one that big and I don't feel bad saying that since the rocket was unmanned. Also interesting is that the rocket was made by Orbital Science, under contract of NASA. This shows that the space industry is slowly because more of a private industry with Orbital Science and SpaceX leading the way at the moment. They aren't sure exactly what caused the rocket to fail, but the actual explosion was caused by the self-destruct being purposefully activated. The real problem was right when it fired its first stage - you can kind of see this in the video. As soon as this problem was noticed, it was decided to destroy the rocket before it reached a populated area and could potentially cause damage. Any number of factors can mess up a rocket launch; there are a lot of variables. Wind speed and direction, an area clear of people, weather, calculations, etc. I think the biggest things I learned from this are that those errors we usually don't account for in our physics labs (FRICTION!!) matter a lot in the real world, and that we still have not perfected going to space. I'm excited for space tourism anyway.
  7. 2 points
    So are you saying that in one of these dimensions you're actually good at super Mario??. Fascinating stuff Jake, and don't go putting your cats in radioactive boxes, alright big guy?
  8. 2 points
    Hello, my name is Max and I'm a senior in high school. Since everyone else is talking about the sports they play...I will too. My mother often asks me to stop playing tennis because it is such a physical sport, but I rarely listen to her so I continue to play at a varsity level. I can't have any pets except a boring fish because my dad is allergic to the fur on cats and dogs. At the moment I work at a restaurant called Hose 22 and I usually prepare food. I'm taking physics because it was recommended to me by my counselor. But I am excited to start physics because it looks like its going to be very different from all the other science classes. I also really want to learn more about the different forces that can act on objects.
  9. 2 points
    Jelliott, I can really relate to your analogies. I too wish to become a beautiful butterfly, to grow and grow until I burst with knowledge. although I find some of your post humorous as intended, I think you struck on very important ideas. I think hard problems can be torture but on the other hand, that makes them that much more rewarding when completed.
  10. 2 points
    If you wanted to, you can change your name and remove your last name in the settings! Enjoy physics!!
  11. 2 points
    Maybe I'll write a post just about cows...*suspense*
  12. 2 points
    Sweet blog post. If you wouldn't mind spreading the love and also buying your two student teachers silver Porsches, we wouldn't complain
  13. 2 points
    Soooo, because this is my last blog post for this year ( ), I thought it would be fitting to do a course reflection on the AP-C physics class this year. I thought I'd do it in a "bests-vs-worsts" top 5 format, kind of like you could find on collegeprowler.com when viewing different schools. Top 5 Bests: 5.) Blog Posting [i thought this was really fun! I've never done anything like this before for a class. It brought up interesting physics applications and I thought it was fun to converse with classmates on the site ] 4.) Independent Units [As uncomfortable as I was at first, independent units forced me to manage my time, work harder than usual to learn the topic, and was great preparation for college. I feel like everyone sould experience this kind of a unit before graduating] 3.) Assigned practice problems from the readings [Assigned problems were REALLY helpful. I would've struggled a lot more than I did had I skipped doing the sample problems] 2.) Units with Lecture & book follow-up [This is my favorite way to learn things! The read-then-lecture method] 1.) VIDEOS <3 [Hands down the most helpful resource in Physics] Top 5 Worsts: ...I think this is my biggest beef. I really don't have 5 things to complain about. 1.) Readings weren't assigned [When life gets busy in the middle of the year, especially with a number of APs, sports, etc., readings are the first thing to get cut out for me if they're not assigned. Confession: when the going got tough, I would often skim or not read. I reccomend assigning readings in the future. Kids will complain, but they'll thank you when they see better grades and their AP score.] Overall, this was a successful year. A note to future students: This is by far the hardest AP course I've taken throughout high school. If you want to succeed, you must: A.) Read the textbook and do some practice problems B.) WATCH THE VIDEOS. Whether you're confused or simply want review, these are soooo outrageously helpful. It's like being in class a second time, except in 15 minutes or less instead of 42. Plus, you can skip over any sections that you feel you know solid. C.) REVIEW THE EQUATIONS AND FREE RESPONSE BEFORE THE AP. I went through most of the E&M free response questions as well as both E&M and mechanics equations before the exam. KNOW THE EQUATIONS! I swear equations and key concepts are the majority of the test when it comes to the multiple choice Qs. Any favorite parts of the year? Things you wanted to change? Post below with your opinion! ...I can't believe we only have 1 more day of physics
  14. 2 points
    PCX is a workout area that I participate at weekly with my volleyball team. We go on tuesday nights to exercise as a team. I realized while watching videos that i recorded of the exercise's how much physics was applied into each activity. The vertamax that we use for jump training is full of physics. When you use the vertamax you put on a belt with two clips on either side of your hips. You then stand ontop of the vertamax (a square flat surface) and then attach the clips to different color resistance bands. With the vertamax at PCX you can either choose to use it for jump training or leg strength by making the bands go parallel to the floor instead of perpendicular. Once cliped into the machine we are told to jump and go for maximun height. The force of the resistance bands pulls us toward the ground and makes us work harder to get higher into the air. Once we are done useing the clips we unclip the bands and then jump without resistance and analyze the height difference. The jacobs ladder is another machine that we utalize on a weekly basis. Similar to the vertamax you belt yourself into this machine and then "climb the ladder." You can control the speed of the machine with how much force you put into it. If you are working hard and pushing yourself and the machine then the output on the machine will mirror your work and move faster to challenge you. The machine is inclined at a angle so as to simulate climbing up a ladder type object The angle that it is inclined to makes it more difficult to climb. The Pull up bar is also full of physics. With three reps of eight pull ups my team is challenged to bring their entire bodies up into the air transitioning from potential energy into kinetic. We are given band to put our feet into for extra support. The rubberband like bands expand and retract to help differ our weight. The sled is yet another item that we use to work out. Notice this is not your typical snow sled. This sled is a black device that you put weights on inorder to work your legs and arms. Having the sled on the turf surface creates more surface tention and therefore more work to be done by my teamates. There are two different holds that we can choose from when using the sled. The two different holds are all about angles. The higher of the two is easier because you are able to use the machine against itself to push it across the turf. The lower of the holds means that the players body is parallel to the ground and very close to it. The force that it takes to push your legs and arms together to get the seld across the turf is increased from the higher angle hold. Basically every tuesday i have extra amounts of physics added to my day!
  15. 2 points
    My childhood, like many others, was spent watching many Disney Movies. One of my all time favorites was the Lion King- I never grew tired of it. One scene that always sticks in my mind is that once music number of young Simba and Nala and, of course, the scene of Mufasa's Death. (0:49-1:20) It can usually bring tears to even the toughest of teens, yes? As a child, this scene really never bothered me and, now, this sad scene seems to bother me so much more. Mufasa died a heroic, and untimedly, death by saving his only son. However, we should move onto the Physics now. How accurate is Mufasa's death, exactly? Could a fall from that height really kill an adult male lion? How far did he fall, anyway? It's very hard to tell but, after reviewing this scene many times I feel I can give a good shot at answering these questions. From what I can tell, Mufasa's fall lasted roughly 5 seconds (1:07-1:12ish), and started from rest before... Scar decided to be a jerk and condemn Mufasa to death. So, using the equation d=vit+(1/2)at2, knowing his falling time was 5 seconds, he started from rest, and acceleration due to gravity is 9.81m/s2; It can be estimated that Simba's father fell about 123 meters. While he seemes to be fairly high before he fell, I highly doubt that the the distance (vaguely seen at 0:50) was taller than the Statue of Liberty. Obviously, it makes sense why a Disney movie would over exaggerate the death of a character, and not care about making the Physics of a children's movie accurate. While real Lions are tough and resiliant, a fall like Mufasa's (even if less than 123meters) would still kill or severely injure an adult lion- not taking into account the stampeeding wildebeasts trampling. So, as expected, Disney's The Lion King takes little care in being realistic... It was still interesting to think about, however! And imagine how cool (at least, I think so) it would be if a childhood classic was actually completely accurate- in a physics sense (because animal's can't talk).
  16. 2 points
    Thrilled to help, and welcome to the APlusPhtsics Community! The short version... The College Board says you need to know how to derive them. Very rarely have they asked students to do so, but it has happened... This guide sheet may help with studying: http://aplusphysics.com/courses/ap-c/tutorials/APC-Dynamics.pdf Good luck!
  17. 2 points
    I have a very large interest in bees, so for my first blog post I've decided to research how bees see colors differently compared to humans. Through my research I have discovered that the color spectrum of bees is shifted when compared to the color spectrum of humans. Visible light is part of a larger spectrum of energy. Bees can see ultraviolet – a color humans can only imagine – at the short-wavelength end of the spectrum. So it’s true that bees can see ‘colors’ we can’t. Many flowers have ultraviolet patterns on their petals, so bees can see these patterns. They use them as visual guides – like a map painted on the flower – directing them to the flower’s store of nectar. Some flowers that appear non-descript to us have strong ultraviolet patterns. Being a bee doesn’t necessarily mean you live in a more colorful world. Bees can’t see red – at the longer wavelength end of the spectrum – while humans can. To a bee, red looks black. Humans see light in wavelengths from approximately 390 to 750 nanometers (nm). These wavelengths represent the spectrum of colors we can see. Bees, see from approximately 300 to 650 nm. That means they can’t see the color red, but they can see in the ultraviolet spectrum (which humans cannot). Bees can also easily distinguish between dark and light – making them very good at seeing edges. This helps them identify different shapes, though they can have trouble distinguishing between similar shapes that have smooth lines – such as circles and ovals. Vision is important to bees, because they feed on nectar and pollen – and that means they have to find flowers. Bees can use odor cues to find a perfect flower, but that only works when they’re already pretty close. Vision is essential to help the bees find flowers at a distance. A bees Vision in responce to different colors: Red -> black Yellow -> yellow-green Orange -> yellow-green (darker) Green -> green Blue -> blue plus ultraviolet blue Violet -> blue plus ultra violet Purple -> blue White -> blue green Black -> black In conclusion, bees have a very unique color vision.
  18. 2 points
    As advised by Mr. Fullerton, I did the Coat-hanger bubbles experiment to further understand flux! Pre-experiment preparation: First, in my closet I found a nice metal coat-hanger suitable for the trial. After attempting to reshape the coat-hanger, I learned that my hangers are very strong, or that I lack strength; so, I went to my brother's toolbox and grabbed pliers to help bend the wire into a slinky-like shape. My coil ended up having four turns. I then ventured into my kitchen to fill the sink with soapy water. With the bubbly solution complete, I was ready to start the experiment. The experiment: I dipped my wire coil into the water, and slowly pulled it out. I found that the bubbles didn't form well to the structure. So, I compressed the coil by pushing the turns closer together. When I tried again with the compressed coil, the bubbles formed nicely between each turn and along the outside of the coil. The formation of the bubbles between each turn demonstrated how the number of turns matter when calculating flux. Therefore, the more turns, the greater the flux. Hence, the equation for magnetic flux is: N=number of turns A=area within one loop B=magnetic field =angle between magnetic field and positive normal direction Everyone should try this experiment before the test on Wednesday!
  19. 2 points
    11/10 already and all i've read was the title.
  20. 2 points
    While I was pouring ice cold lemonade for myself, I wondered-- "What would happen over time if I waited for a cup filled completely to the brim with ice to melt? Would the water spill over the cup as the ice melted? Or would the ice just melt leaving the cup still completely filled to the brim with no spills?" Huh. I had to test this out. I decided to use a cup filled with ice, and slowly poured water to the exact brim of the cup, and left a napkin under to see if the water would spill over after the ice melted. This was not enough for me. What if the cup were filled with ice and grape juice? Or ice cube grape juice filled with water? Or ginger ale? Or milk? I was curious. I tested these all out, only to find I was wrong in my original hypothesis. I was sure I'd come back to my kitchen a pooling mess of water, milk, grape juice, and ginger ale, but I was very wrong. I had three cups of perfectly filled glasses completely filled to the very very tippy top, like no other cup has even been. It was amazing. I realized something was up with water. These things called hydrogen bonds really mess with us chemist and physicists. Why? Because they can. In liquids, molecules slip, side, bond, break and reform. However when the water turns to ice, the molecules are rigidly bonded. This creates more empty space between the molecules when the hydrogen atoms bond together so rigidly and thus frozen water occupies more room. It is also less dense than liquid H2O because of this space. This is why ice floats in your Sodas. Or why in the winter-- better known as the constant weather in Rochester-- lakes and ponds freeze at the top and not on the bottom. Because ice is less dense due to H2O's molecular structure of Hydrogen bonding (positive to negative --oppositely charged ends of the water molecules-- creating space). Solid ice takes up more space than the liquid state of H2O. You would think that water would behave like every other substance from liquid to solid-- that the molecules would become denser and more compacted-- but no, it does the exact opposite. Because water is tricky, and that's why we drink it. You may be wondering why the milk and grape juice? Those are mostly water based as well, that is why. Due to the change in thermal energy, we all know that the water transferred energy from the high temperature (water) to the low temperature (ice). This is the second law of thermodynamics. It is also considered an energy heat flow. As we know, this happens so that this water glass can reach a happily balanced equilibrium. This is why ice melts. Even milk ice. The energy in the glass is never destroyed; the first law of thermodynamics tells us energy is conserved. Here are some cool links (pun intended) on ice and why it is less dense than its liquid state of H2O. (Also why it would not spill over a glass even when filled to the brim and left alone for an hour or so.) Not all science experiments have to be messy. http://www.word-detective.com/howcome/waterexpand.html
  21. 1 point
    That's the richest pauper I've ever heard of...
  22. 1 point
    Dear Mr. Vank -- it's fantastic that you landed on the moon... but did you land on time?
  23. 1 point
    @FizziksGuy I did pretty well on it. I did work up to the end of the test because I missed the beginning to go to the nurse though.
  24. 1 point
    Hey guys! Over spring break we drove to Disneyworld in Florida. The car ride was unbelievable long so we decided to stop at a few places. One of the stops was the Kennedy Space Center in Cape Canaveral. For the first time in my life I saw a real rocket last week, which has been a dream of mine since I was little. One of the things I always wondered was how rocket engines work and what makes them so unbelievable strong..? Like most engines, rockets burn fuel. Most rocket engines turn the fuel into hot gas. The engine pushes the gas out its back. The gas makes the rocket move forward. Rockets work by a law that we have all learned a couple months ago; Newton's third law of. If you remember it, it says if Object 1 exerts a force on Object 2, then Object 2 must exert a force back on Object 1. Moreover, the force of Object 1 on Object 2 is equal in magnitude, or size, but opposite in direction to the force of Object 2 on Object 1. In other words, for every action, there is an equal and opposite reaction. The rocket pushes on its exhaust. The exhaust pushes the rocket, too. The rocket pushes the exhaust backward. The exhaust makes the rocket move forward. Actually quite a simple concept.
  25. 1 point
    Hi Isaac - I appreciate the connections between physics and dodgeball that you are making. I know that I have seen some pretty intense slow-motion, time-stop videos that demonstrate the collision impacts you describe. I found one embedded in this prezi - https://prezi.com/nn6xcsmrgdzx/the-physics-of-dodgeball/It is in the "Collision" portion. There are also interesting connections to your concept of absorbed forces to other sports, including baseball and NASCAR. One is in favor of the absorption -one not so much....
  26. 1 point
    NEATO! way to apply physics to one of your favorite hobbies
  27. 1 point
    This was interesting and funny to read
  28. 1 point
  29. 1 point
  30. 1 point
  31. 1 point
    I'am sitting in the Basement of our house right now, thinking about what I could write as a blog post and next to me Quinn works out. It is amazing what a difference it makes for her if she uses the 25lb or the 50lb weight. I'm sure she could do 15 repetitions with the 25lb on her exercise she does right now, but if it was 50lb even 5 reps would be very hard.... So why does it make such a big difference which weight she uses? --> It is Physics! The gravity on earth pulls down her weights and as bigger the mass of the weight is as grater the force which pulls it down. Unbelievable that Physic is in every little thing we do!
  32. 1 point
    Hello, my name is Harrison I am a senior, there's not to much to know about me I enjoy the outdoors, swimming and sleep. I swim for Irondequoit which peeked my interest in lifeguarding so over the summer I became a guard. The job was fun plus working outside in the summer is never a bad thing...Unless it's raining. The best part about my job, aside from sitting by a pool all day, was having the training and skills to help others in need. I am taking physics because it has always been an interest of mine, plus Mr. Fullerton is awesome so I see no reason not to take the class.
  33. 1 point
    Hiya Brenda, and welcome to APlusPhysics. Do you have younger siblings? They could be pseudo-pets... Bonaventure is a great school, and Olean is a fun little town -- tons of great restaurants (The Beef and Barrel is one of my all-time faves!)
  34. 1 point
  35. 1 point
    I also agree with your second paragraph, but do you remember the nerf wars we had in your backyard in Rogers! Now there's some physics for you.
  36. 1 point
    Hi Peter, and welcome to APlusPhysics! Thrilled to have a guitar player in class as well (I have a piano and three guitars at home, though I like to play loud and with two little ones I don't get many opportunities to play without interruptions!) Maybe I can bring the 12-string into class in the spring when we talk about resonance and talk you into a demonstration? And I'm jealous about having goats in the backyard. Growing up in a rural area we had plenty of neighbors and friends and my brother and I always loved playing king of the hill with the goats -- fun critters when you're a kid. I don't think I could get away with having a goat here in the suburbs, though! Make it a great day...
  37. 1 point
    For the most part, humans have good sight. A lot of time and effort during our modern era is put into making TV and computer screens at a higher and higher resolution in order to make things look as "real" as possible - that is, to make the pixels onscreen indistinguishable from what we would normally see. But how good are our eyes really? Lets find out. Before all of this, I'll direct you to a nice, short, but informative link (https://xkcd.com/1080/), courtesy of xkcd. A good representation of how we see, it outlines the many different parts of vision very nicely. Focusing primarily, however, on the "resolution" of our field of vision, that is, how many "pixels" we can see, we can see it varies. Right in the center few degrees, in the foveal region, we can see stuff quite clearly, which makes sense, because we're looking at it. However, the blurred characteristic of the surrounding areas isn't just because we aren't focused on it, but because there simply isn't as much data provided there - much less, in fact. While our center of vision is comparable to a high-res camera, the surrounding areas are much worse quality, with the entire area outside of the center ~10 degrees containing a fraction of the data that the center area does. Our brain just fills in the gaps. So while at times our vision is quite good, other parts could use some work. And even with the high detail of our foveal region, you still might not need that new HDTV. Based on how far away you're sitting, it might not even be noticeable, so don't waste your money.
  38. 1 point
    So It gets dark before 5 O'Clock nowadays. I state this not becuase I think you, the reader, are incable of interpreting a clock ( I assume you are because you are literate enogh to read ) but because this fact has some bearing on the phyisics of running. When I foolishly decided put off starting my training run untill four fifteen, I found myself in the middle of the woods forty minuites later with the sun sinking below the horizon and three miles of trails left to navigate. Phyisicly speaking, A couple things happened to me at that point. First, the subconience fear kicks in, the effect of too many horror movies, that I will be eaten by cyotes or kiddnaped or murdered by some deranged phycopath. This produces the aldrenaline rush, which sends me flying throgh the woods at an abnormal speed. Because every shadow is a potential lurking threat to my scared brain, I fail to look at the ground, and I forget newton's third law. Applied here, that means that when sneaker toe applies force to an unseen root, this root will push back and cause a runner to accelrate downward in a parabolic arc toward the ground, because his momentum will be stopped suddenly and unexpectedly. Thankfully, I cauhgt myself and managed to keep my fear under controll for the rest of the trip back. But a runner will stay in motion at a constant speed unless acted upon by the completion of his goal, and I ran, abiet carefully, all the way home. Moral of the story: always bring a flashlight. P.S. don't judge me on the spelling my laptop does not have a right click and I have no way to spell check that I know of. You know you all rely on it as much as I do:)
  39. 1 point
    Yesterday I climbed Giant Mountain, one of the 46 Adirondack High Peaks. With a summit elevation of 4,627 feet (1,410 m) Giant is the 12th tallest of the high peaks and with an elevation change of 3000 ft in 3 miles it's also on of the steepest. The journey began at the car near the trail head where I was deciding on footwear. The 2 options were hiking boots (0.92 kg a pair) of Nike frees (.42 kg a pair). The boots would be heavier and require more work to ascend the mountain, but would provide better traction and keep my feet dry. The frees would require less energy but likely slip on everything, provide less support and get my feet drenched within minutes. I chose the boots, so how much more work did I do climbing the mountain? The ideal approach to figuring this out would be to multiply the number of steps that I took while ascending and descending the mountain by the average distance that I lifted my feet with each step; and then multiply that by the force I exerted against the weight of my boots/shoes (work=force*displacement). However I didn't count my steps because counting for 5 hours would have driven me insane and the vertical distance that I lifted my feet varried widely on the diffenrt sorts of terain I encountered. So I'll just use the vertical displacement up the mountain as my displacement. The difference im energy expendature can be found by multiplying the difference in weight of the shoes by the displacement up the mountain. Difference in weight=(.92kg-.42kg)(9.8m/s2)=4.9N Vertical displacement=(3000ft)(1mi/5280ft)(1609m/mi)=914m work=force*displacement Difference in work=(4.9N)(914m)=4497.6J So by choosing the boots I expended about an extra 4500 Joules (about 1070 calories) of energy (but I estimate that in reality It was probably closer to double that). However as we climbed further the trail became covered in snow and ice, making it incredibly wet and slippery, so without the boots I likely would have fallen off the the mountain and gotten frostbite on my feet. In the end think 4500J is a fair tradeoff for not dying.
  40. 1 point
    Throughout the age of cyber technology...one thing has always been a menace to our electronic productivity. There is only one force that can disturb the power of the internet. That force manifests itself as hacking. Ever since computers were available, people (with their natural evil tendencies) wanted to steal others' information. And so they did. A recent hack on Adobe could possibly be the largest ever. 152 Million Adobe accounts were discovered by the security firm LastPass to be compromised by hackers. That's 152 million credit cards...now at the hands of a smart computer user. Although the information has been restored quickly, some hackers have been more lucky. In July of this year, four men successfully hacked into the NASDAQ, among other megacorporations like Citibank, PNC Bank, Heartland Payment Systems, 7-Eleven, and JCPenney. Stealing credit card informatin along the way, these four men "owned" the NASDAQ while they had control over one of the world's largest financial database. I've had a personal encounter with hacking on this website. An anonymous user has breached my account and has recently posted a blog post... Some people want to watch the world burn.
  41. 1 point
    I'll give you some hints... First, you need to find the acceleration of the passenger as the car stops. To do this, first convert the initial speed of the car from km/hr to meters/second (http://www.aplusphysics.com/courses/regents/videos/Metric_System/Metric_System.html). Next, calculate the acceleration of the passenger: http://www.aplusphysics.com/courses/honors/videos/KinEqns_Hon/KinEqns_Hon.html Finally, once you know the passenger's acceleration, you can calculate the force using Newton's 2nd Law: http://www.aplusphysics.com/courses/honors/videos/N2Law_Regents/N2Law.html
  42. 1 point
    My name is Danielle and I am 17 years old. I am a senior and a captain of the swim team. Outside of school, I spend time working as a lifeguard, teaching swim lessons and skiing in the winter. I wish to pursue a career in economics or photography. I am currently taking regents physics. I am taking it because I wanted to take another year of science because it looks good for college. I decided on physics because I did not want to take biology or chemistry again. I think I will really love Physics this year because Mr. Fullerton seems really nice and fun.
  43. 1 point
    When your in the shower belting out songs so know one can hear you i bet you have never thought that singing would have anything to do with physics. Well youre wrong! It totally does! People can not only hear your singing but they can also feel it! By singing, your voice creates vibrations that form into waves. Sound can be represented in wave form. The amplitude of the wave (the height of the wave) is represented by how loud you are singing. The amplitude is the degree of displacement of teh vibrator. Singing at a louder pitch create more vibrations, while singing at a soft pitch doesnt create as much vibration. This can be heard and felt in a car also. Depending on what the volume and the bass in the car is set at a person sitting in the car can feel the vibrations. Usually you cant feel the wave vibrations of a voice that isnt amplified unless you are on a surface that can allow waves to pass through it easily. For example, you can feel vibrations through would very well. So next time your mom or dad say stop singing you can tell them i am just practicing my physics
  44. 1 point
    Pre-Launch Design Release ****NOTICE: We ditched our old goal of making an unmanned orbit because a spacestation in orbit is cooler****** Team Name: Kailzah Available Funds: 37426 Vehicle Name: October Sky II Vehicle Parts List and Cost: Aerodynamic Nose (680x1), Ox. 4 Photo P. (300x2), Probodoyne OKTO2 (230x1), adv. SAS mod. (1,100x1), RCS Thruster (450x3), RCS Fuel Tank FL-R25 (800x1), Inline Clamp O Tron (700x1), TR-18A Stack Decoupler (600x3), FL-T400 Fuel Tank (850x1), FL-T800 Fuel Tank (1,600x1), liquid fuel engine (475x1), Rockomax Adapter (50x1), Rockomax Jumbo 64 Fuel Tank (12500x1), Mainsaid Liquid Engine (850x1) Design Goals: We used a rather large engine in combination with two connected smaller fuel tanks and three decouplers to ensure that October Sky II makes it into orbit. Launch Goal: With this launch, we hope to put a space station into orbit around Kirbin. We hope to learn how to make a proper orbit around Kerbin (this being our first official launch). Also, we hope to use this space station in the future with our further launches. Pilot Plan: 1. Turn on SAS and go full throttle 2.) During overheat, turn down throttle to 75% 3.) Decouple and loose the first fuel tank when fuel is low/out 4.) Go full throttle and enguage RCS 5.) Turn on propgade 6.) After exiting the atmosphere, cut engine 7.) Examine orbital position & approach apopolis 8.) full throttle & widen untill path is suitable for orbit Illustrations: Safety Rep:
  45. 1 point
    I'm sure we will. Most of this team has been taking AP tests for a couple days.
  46. 1 point
    Hmmm... I wonder why I can make my hose spray farther when I put my thumb over part of the end?
  47. 1 point
    Great blog post, and I learned something new about nordic skiing. Always take good care of your skis, and hopefully they'll take care of you!
  48. 1 point
    i have a problem. every time i pick up a cat to let it fall to its death, it manages to turn around mid air and land square on its feet, even when im not giving it any initial rotational speed. the law of conservation of angular momentum says that the cat can not start rotating after i have dropped it, assuming it starts with no angular momentum at all. so how they do it? turns out, they actually bend themselves into a v shape in mid air, breaking their rotational axis in two. this lets them turn their front half against their bottom half via muscles in their torso, resulting in both rotational motion along the center of mass, and along each side of the v they created with their body. this allows them to quickly spin around while still conserving their total angular momentum. when theyve turned 180 degrees, the cat simply bends out from the v shape, into what is more or less a line, in which state the cats is not turning at all, because the net angular momentum must be zero, conserved from the beginning. therefore, cats are immortal.
  49. 1 point

    Version 1

    94 downloads

    Handout / guide sheet for students studying electric potential in courses such as AP Physics C: E&M

    Free

  50. 1 point
    so the other day i let my rabbit have free range of my room for a few hours as i was doing my webassign, and after a while the mouse i was using for my computer stopped working. i checked the plug, and to my confusion it was still plugged in. as i attempted to diagnose the problem i looked below my desk for a moment, finding my rabbit with a mouthful of copper and plastic. tasty. unfortunately he had not only chewed through my mouse cable, but also that of my webcam, among others. i got out my soldering iron and strippers, and as i removed the insulating tubing from each wire i found something interesting. on the mouse wire i removed the insulation to find only the four wires typical of a usb cord, however as i peeled back the insulation on the webcam wire, there was a second layer of braided wire and foil around the center four wires. at first i thought this may be an other data-carrying wire, or possibly a ground, which wouldnt make sense since usb uses very low voltage. i then realized it was just a conducting shell there to block interference with the webcams image quality from outside radio noise using the faraday cage effect. i hypothesized that my mouse didnt have this extra layer because the location of a mouse pointer is somewhat arbitrary on the small scale, so blocking this small ammount of interference would not be cost effective for the company that made it. moral of the story: faraday cages can be pretty useful.


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