Jump to content

Leaderboard

Popular Content

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

  1. 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!
    3 points
  2. I played dodgeball too!
    2 points
  3. 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.
    2 points
  4. ...(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.
    2 points
  5. 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..
    2 points
  6. 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.
    2 points
  7. 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?
    2 points
  8. 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.
    2 points
  9. 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.
    2 points
  10. If you wanted to, you can change your name and remove your last name in the settings! Enjoy physics!!
    2 points
  11. Maybe I'll write a post just about cows...*suspense*
    2 points
  12. Sweet blog post. If you wouldn't mind spreading the love and also buying your two student teachers silver Porsches, we wouldn't complain
    2 points
  13. 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
    2 points
  14. 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!
    2 points
  15. 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).
    2 points
  16. 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!
    2 points
  17. 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.
    2 points
  18. 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!
    2 points
  19. 11/10 already and all i've read was the title.
    2 points
  20. 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
    2 points
  21. Gym class is filled with exciting games every year. One of my favorites is badminton. One of the amazing things about badminton is that is uses a shuttlecock, or birdie, that is volleyed back and forth over the net. What's amazing about the shuttlecock is that it always flips on impact so it flies with the cork facing forward for the opposing team to hit it back. What makes it flip? The mass of the shuttlecock is not evenly distributed. Most of the mass is in the cork part of it. The shuttlecock also holds a shape that is similar to cone. This causes more air resistance to the back, or feather, part of the shuttlecock. As a result the cork is moving at a higher speed on impact and moves in front of the feathered part. From this series of photographs you can see that when the shuttlecock is hit it is initially facing the racket, but immediately starts to rotate. As the projectile moves along, the shuttlecock completely changes direction for the opponent to hit it right back.
    1 point
  22. The first point of sectional finals, we have serve. Ace. A couple more aces and a big serving run and we are now up 18-3. We end up winning the first set 25-6. 25-6. 25-6, in sectional finals, against Pittsford Sutherland. It is clear now who has the momentum moving forward. The momentum from the first set carried us in the next two sets and we end up winning the match and sectional finals. In a sport, when a team has the "momentum" in the game, it means that they are the ones on the move and will be hard to slow down and stop. In physics, momentum is the product of mass and velocity, and the equation is p=mv. Therefore, as mass or velocity increases, so does momentum. Momentum is also a vector quantity, so it has a direction to go along with the magnitude. A change in momentum is the impulse which uses the equation J=Ft. It would take a large amount of force in a large time to create a big impulse or change in momentum. Last night, Sutherland started to create an impulse in the second and third set, but it wasn't enough to sway the momentum in their direction. Here's a video of the final point of the match last night!
    1 point
  23. From - https://answers.yahoo.com/question/index?qid=20110917100043AAuhgCE
    1 point
  24. New Aluminum Battery Could Recharge Your Phone in Just One Minute The next generation of batteries is here! An ultrafast rechargeable battery that’s also cheap and long-lasting. And since the new material it is made of is aluminum, the new battery is a safer alternative to conventional lithium-ion and alkaline batteries we are using all around the world today. For decades, Scientists have tried to use aluminum as material for batteries. The great benefits of aluminum over conventional lithium-ion and alkaline batteries that we are using today are that aluminum is cheap, bendy, and has low flammability and high-charge storage capacity. So far all attempts to develop a commercially viable aluminum-ion battery have been unsuccessful. But now for the first time in history, an international team led by Stanford’s Hongjie Dai have accidentally discovered a simple solution. I’m not a Scientist, but if you are really interested in the procedure, I would highly recommend you to check out this article (http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14340.html#figures). The battery is also ultra-fast charging and crazy durable. Unlike the hours some of us might spend charging our phones every night, the prototype of the aluminum battery has a charge time of one minute! And not just that but what most of us don’t know is that the batteries for example in an iphone 6 are made to last for about 500 to 700 cycles, were the international team of scientists says that their new battery is able to do more than 7,500 charge-discharge cycles without losing its capacity. Unfortunately, the technology is still not completely developed and won’t be on the marked any time soon. One battery generates about two volts of electricity. While that’s more than any other aluminum prototype thus far, that’s only about half the voltage of a typical lithium battery. That doesn’t mean that it won’t come at some point though but it will take a little more research over the next years and then there should be nothing to stop the new era of batteries that are not just faster but also better for our environment. Also the scientists are confident in their next steps “Improving the cathode material could eventually increase the voltage and energy density,†Dai explains. “Otherwise, our battery has everything else you'd dream that a battery should have: inexpensive electrodes, good safety, high-speed charging, flexibility, and long cycle life. I see this as a new battery in its early days.†If you want to know more check out this video:
    1 point
  25. Before I finish off my Shrek series I had a few more thoughts on adhesives. One being, the fzx behind Post-it® notes. I recreationally collect sassy Post-it® notes. You'd be surprised...but they are always applicable. Imagine having the printed phrase, "If ignorance is bliss, why aren't more people happy?" on hand every second of the day. It's exhilarating. Or something like, "Why yes, I am overqualified." And maybe, "I think you heard me the first time." They're so so so useful, and I highly suggest investing. Anyways, I've only had a mere use, not quite a reason. WHY do post-it notes work? I did some research from a website that described life on Earth as, and I quote, "[A] bit like being a giant living Post-it® note—only with legs!" so I think my information is fairly reliable. With my collected data, I learned that: A.) The back of a sticky note contains a continuous film of adhesive as well as microscopic glue bubbles. [These can only be seen with an electron microscope]. B.) These glue bubbles are called microcapsules and they are about ten to one hundred times bigger, but much weaker, than the glue particles on the average and conventional Scotch Tape®. C.) When pushing a sticky note into place, som of the larger microcapsules cling; just enough to support the weight of the tiny slice of cute yellow paper...hopefully decorated with a sassy phrase. Well. There you have it folks. Just a quick and simple lesson on one of my quirks as well as as the fzx behind it. One piece of advice I'd like you to take home with you tonight: Just remember, that every time you attach and peel off a Post-it® note, dust and dirt attach to the adhesive capsules. Therefore, the notes prgressively and gradually lose their stickiness. Sure, it WILL go on sticking for awhile. Alas, Post-it® notes are a thing to be valued. So don't waste their magic. I mean fzx.
    1 point
  26. When visible light, X rays, gamma rays, or other forms of electromagnetic radiation are shined on certain kinds of matter, electrons are ejected. That phenomenon is known as the photoelectric effect. The photoelectric effect was discovered by German physicist Heinrich Hertz(1857–1894) in 1887. You can imagine the effect as follows: Suppose that a metal plate is attached by two wires to a galvanometer. (A galvanometer is an instrument for measuring the flow of electric current.) If light of the correct color is shined on the metal plate, the galvanometer may register a current. That reading indicates that electrons have been ejected from the metal plate. Those electrons then flow through the external wires and the galvanometer, providing the observed reading. The photoelectric effect is important in history because it caused scientists to think about light and other forms of electromagnetic radiation in a different way. The peculiar thing about the photoelectric effect is the relationship between the intensity of the light shined on a piece of metal and the amount of electric current produced. To scientists, it seemed reasonable that you could make a stronger current flow if you shined a brighter light on the metal. More (or brighter) light should produce more electric current—or so everyone thought. But that isn't the case. For example, shining a very weak red light and a very strong red light on a piece of metal produces the same results. What does make a difference, though, is the color of the light used. One way that scientists express the color of light is by specifying its frequency. The frequency of light and other forms of electromagnetic radiation is the number of times per second that light (or radiation) waves pass a given point. What scientists discovered was that light of some frequencies can produce an electric current, while light of other frequencies cannot. Einstein's explanation. This strange observation was explained in 1905 by German-born American physicist Albert Einstein (1879–1955). Einstein hypothesized that light travels in the form of tiny packets of energy, now called photons. The amount of energy in each photon is equal to the frequency of light (ν) multiplied by a constant known as Planck's constant (â„), or νâ„. Einstein further suggested that electrons can be ejected from a material if they absorb exactly one photon of light, not a half photon, or a third photon, or some other fractional amount. Green light might not be effective in causing the photoelectric effect with some metals, Einstein said, because a photon of green light might not have exactly the right energy to eject an electron. But a photon of red light might have just the right amount of energy. Einstein's explanation of the photoelectric effect was very important because it provided scientists with an alternative method of describing light. For centuries, researchers had thought of light as a form of energy that travels in waves. And that explanation works for many phenomena. But it does not work for phenomena such as the photoelectric effect and certain other properties of light. Today, scientists have two different but complementary ways of describing light. In some cases, they say, it behaves like a wave. But in other cases, it behaves like a stream of particles—a stream of photons. Read more: http://www.aplusphysics.com/courses/honors/modern/duality.html http://www.scienceclarified.com/Oi-Ph/Photoelectric-Effect.html#ixzz3MLV49L00 http://www.physlink.com/Education/AskExperts/ae24.cfm http://www.colorado.edu/physics/2000/quantumzone/photoelectric.html
    1 point
  27. I absolutely loved reading this -- not only for the awesomeness that is our universe, but that awesomeness that is your enthusiasm. Great post!
    1 point
  28. Even though Kylee and Mandy always go at it, it's cool that you found the physics in it!
    1 point
  29. I never thought I'd have to say this, but I feel really excluded by all of the video gamers.
    1 point
  30. Article: Breaking News! West Irondequoit physics students have calculated the acceleration due to gravity! In a physics lab students participated in, they used only a stopwatch to find the acceleration due to gravity. They dropped a ball from the ceiling of their classroom and used only the initial velocity, height of ceilings and the time it took for the ball to drop from the ceiling to find the acceleration due to gravity with an equation. When calculating this, they had only 3.98% error from the actual 9.81 m/s2. They got 10.2 m/s2 for the acceleration due to gravity. The students that preformed this lab had a breaking discovery that could change physics forever. By being able to calculate the acceleration due to gravity with only a simple stopwatch, physicists around the world can now do the same. This new strategy makes calculating this acceleration with simple algebra.
    1 point
  31. Hi my name's Kalea (kuh-lay-uh) and I am a senior here at IHS. In my spare time I love to run track and play field hockey. When i'm not in school i'm working, and when i'm not working i'm sleeping. When I'm not sleeping I'm usually buying something online or in person that I really don't need! I am looking forward to my senior year! I took physics because I generally enjoy sciences, and I didn't want to take environmental or AP Bio but I wanted to take a science. Which left this and AP Chem so with the toss of a coin this won! I hope to learn stuff about space and how gravity and other forces affect the human body. I'm hoping to come out the Regents feelings great! video of a skill needed to be successful on the field:
    1 point
  32. My name is Megan, and I'm seventeen. I have two brothers, and a golden retriever. I go camping a lot by the lake, and I enjoy going kayaking and boating. Also, my job is that I landscape over the summer. The reason I took physics was because I heard that this was a very interesting class to take. I hope to learn more about how things work in the universe in depth. I think that this class will also help me figure out if I want this to be apart of my career. I feel that this class will be a very important part of my senior year.
    1 point
  33. Hello everyone! My Name is Moritz, I am the Austrian Exchange Student. I love sports, I play Rugby for RC Danube in the U18 Pirates Team, but also do lots of other sports like Windsurfing, Mountain-biking (Downhill), Skiing, Snowboarding, Kitesurfing, Sailing and lots of other Sports at any time of the year. In Austria I go to an "Art School" where the main focus is on photographie and art. I take Physics because it is part of my Exchange Programm and I have to, but I anyway think that it is very interesting as Physics is basacally everywhere! My goal for this year is the get a better view of Physics and I would like to do a lot in the lab and learn lot's of new things
    1 point
  34. Right, I would integrate from time t=0 to some final time t=t, so your limits of integration are 0 to t.
    1 point
  35. Hello, I got to this question and was not sure how to go about it. I sorta had an idea but that was for the line charge of a fixed length, so do I just ignore the lengths and assume that E= lamda/(4 pi e0) and then use V=int(E*dl)?
    1 point
  36. What is Pavel time? Pavel time is the time right before a deadline when actual work gets done. How does this relate to physics? It relates specifically to Albert Einstein's theory of relativity. Part of the theory of relativity states that measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. So, in real life, as an object approaches the speed of light, it gets squished and time slows down for the object. How does this relate to Pavel time? In my theory of relativity, as more work gets done more quickly, time slows down and allows me to finish whatever assignment I have before the deadline.
    1 point
  37. Here's something I just stumbled upon a few minutes ago. Its Olympus Mons, Mars' largest mountain. Olympus Mons is also the largest volcano in the solar system and the 2nd tallest mountain in the solar system (behind the Rheasilvia peak on the asteroid 4 Vesta). Olympus Mons is a shield volcano and was formed the same way that the Hawaiian islands were, by lava flows hardening and building up over hundreds of millions of years. The difference is that while the Hawaiian chain was formed by Earths crust moving over a hot spot in the mantle, Mars does not have mobile tectonic plates so the hotspot that releases lava is always in the center of the mountain. Olympus Mons is located near the martian equator and is 370 miles wide and 13 miles tall, with cliffs up to 5 miles tall. The base covers an area roughly the size of the state of Arizona and is 2.5 times taller than mount Everest. The atmospheric pressure at the highest point is estimated to be 0.03kPa, which is 12% of the average martian atmospheric pressure of .6kPa. What's interesting about this is that the air pressure at the summit of Olympus Mons is a much higher percentage of the surface pressure than it would be on Earth. The atmospheric pressure on Earth at an altitude of 13 miles is approximately 4.5kPa, just 4.43% of the average sea level pressure of 101.33kPa. This happens because the acceleration due to gravity on mars in 3.7m/s2, less than half of that on Earth, which increases the scale height of Mars' atmosphere, so there is relatively higher atmospheric pressure at higher altitudes. It's amazing to think that there are mountains out there on other planets that dwarf anything we have on Earth. I've always been interested in space but my interest just peaked (pun intended) as I look out at the night sky and wonder what else is out there.
    1 point
  38. I'm ready to take on physics with ya
    1 point
  39. After many, many long hours and tons of great feedback from physics teachers across the globe, I'm thrilled to announce the AP Physics 1 Essentials, a guidebook / review book for the upcoming AP Physics 1 course, is due for release in late August. I began work on this project in the summer of 2010 when conversations at the AP Annual Conference in Washington, D.C., led to a number of different teachers talking about the need for a detailed course breakdown to support the change, followed by discussion of what the true cost of the change would be in terms of instructor hours, curriculum rewrites, resource revisions, etc. It was obvious there was going to be a need for a guidebook for the course, and my goal was to provide a short "everything you need to know" book that was easy-to-read, fun, engaging, and inexpensive so that students could pick this up as a guidebook/review book without having to purchase entirely new textbooks to support the changing course. I quickly picked up a following of fans eager to see the project succeed and more than willing to contribute what they could, from early draft versions of the Division of Content plans (which only vaguely resemble the final curriculum guides), to proposed and/or recommended formula sheets, to technical reviews, editing, "wish lists," etc. I've been amazed at the positive response and helpfulness of so many, that has allowed this project to progress through multiple obstacles, from revised content and organizational issues through technical hurdles such as a corrupt book file caught nearly 80% into the rough draft. I guess this qualifies as checking the "nothing worthwhile is easy" box on the project. I'm grateful to my family for allowing me the many hours early in the morning, late in the evening, and during the summer to work on this effort. As I write this, for example, I'm on vacation with my family. It's almost 6 am, I'm watching the Allegheny River flow past, and just saw a bald eagle fly up the river, not 30 feet from where I sit typing. I also must thank the many physics instructors across the globe who have contributed in so many ways, from editing to hints to encouragement... but I need to say a special thank you to the APlusPhysics community. The website began as a tool to use in my own classroom, and quickly grew so popular that I felt compelled to continue to expand it at the request of its users. With more than 30,000 students using it EACH MONTH, I've been absolutely floored by the number of thank-you messages, letters of encouragement, and success stories contributed voluntarily by community members. You guys set me on this path, made the site and the books successful, and it's your encouragement and support that have kept me at this project through the wee hours of the night and long hours of frustration. Moving on to the final product… I'm proud to say the book is finished. Sure, it has a few more edits to make, a few more tweaks here and there, but everything is on track for a late August 2013 release. My long-term goal was to have the book released one year before teachers began teaching the revised AP course, and it appears we'll hit that deadline on the nose (with special thanks to the AP for delaying the change a year from the date I was originally told back in the summer of 2010). I'm hoping you find it valuable to your courses and studies. This book was written as the guidebook I would want my students to have for the course. Not a full standard physics textbook, because my students don't learn and fully read their physics textbook (except in snippets), but rather a book designed to be used as written, read AND understood, with tons of example problems and solutions. Thank you so much for your tremendous support. I hope you enjoy AP Physics 1 Essentials as much as I enjoyed the opportunity to work with you and so many other amazing people on this project. Make it a great day!
    1 point
  40. wow what a great topic to write about! i will keep this is mind next time i go swimming, thank you so much for enlightening me on another interesting topic once again!
    1 point
  41. Docking can be one of the more difficult maneuvers to learn when it comes to judging when the correct time to burn engines to rendezvous with target, but if you can successful it can be an efficient way of landing and knowing you still have fuel left in your drive stage to return you home. I would similarly recommend training yourself by attempting to build a small (key word there. Small) space station.
    1 point
  42. For your first attempt at putting a satellite into orbit this is actually quite impressive. As for matters of efficiency, before I could see the pics I seen in your parts log that you were bringing a lot of fuel and you would no question be able to achieve your goal even if you halved your final stage. You did however do a fair job with what you used. Nice use of fuel lines to feed the central tank. You may find in future that if using wings that you don't need a gimble functioning engine or vice versa as either one on their own would allow you to turn easily saving weight, mass and reducing drag if you only used the engine. (Saves buying 4 wings too! ;-D ). Remember to check the isp of the engines too, for your initial booster stage there may be other engines that are highly efficient when within the atmosphere. (I'll let you check which.) Lastly remember terminal velocity. Overthrottling too early can cost you a lot of fuel for not a lot of gain.
    1 point
  43. This is a really good trailer. Although I got into ksp before the trailer, It still really inspired me.
    1 point
  44. Last night I was at an awesome concert, but as I looked around, I realized how much physics can truly relate to everything going on around me. First of all, if you are at a concert, you expect to hear some music. That must mean that sound waves have to be traveling through the air for everyone to hear it. As I was sitting there enjoying the concert, I realized that the speed of sound in air at STP is 3.31x10^2 m/s! This made me extremely happy to have some background information on sound waves that most people don't have because they didn't take regents physics. I also knew that the closer I got to the stage, the higher the frequency and amplitude would be, and if I started heading towards the door, the amplitude and frequency would decrease, which illustrates the Doppler Effect. Also, there were some pretty awesome lights shining all over the stage and occasionally over the crowd. I was watching the colorful lights, when all of a sudden the electromagnetic spectrum came to mind. I thought about how out of the whole spectrum, there is only a small part that is made up of visible light. I also thought how all the colors can come together and if they are reflected, that creates white, and if they are absorbed, that creates black. I also realized how fast light must be traveling, at a speed of 3.00x10^8 m/s! This information gave the concert a whole new meaning. As I was looking around at the crowd, I noticed that a lot of people seemed to be crowd surfing, but many of them fell to the ground, which looked pretty painful. I then wondered what their final velocity would be when they hit the ground, so I decided to use one of my kinematics equations to figure it out. First of all, a person's initial velocity would be 0 m/s, because they are just lying on top of the crowd right before they fall. They would probably fall a distance of 2.5 meters, and their acceleration would be 9.81 m/s^2. I then could use the equation vf^2=vi^2+2ad, and once I plugged in all of my known values, I figured out that their final velocity would be about 7 m/s.
    1 point
  45. Omg my feet literally like burn everytime i'm on the beach! Good to know
    1 point
  46. Have you ever wondered what other animals see when they can see more electromagnetic waves than we can see? Well I started with this question and found that a common electromagnetic wave that other animals can see is infrared waves. There are three different types of Infrared waves, near, mid and far. In the following You Tube video Imre describes how you can take pictures of near Infrared waves using your camera. Even though it wasn't exactly what I was looking for the pictures give you an idea of what an animal might see and since my brothers are both photographers it reminded me of them. One of the facts that I found fascinating about Infrared Waves was that the far Infrared waves actually represent thermal waves which represent heat. Thermal Heat can be felt as heat from the sun and also can be found in fast food restaurants. Far infrared waves are closest to microwave waves which can explain why they can be felt as heat. Snakes would then use far infrared waves to see since they detect what is around them by the heat sensing organs in their face. Vampire bats can also use infrared waves to sense their warm blooded prey. Bugs use their antennas to detect infrared rays one reason is to detect prey. Beetles on the other hand detect infrared waves in order to find forest fires. After finding a forest fire they lay their eggs in the burnt wood. A different example is why NASA uses infrared waves to take pictures of objects in space. They take pictures of Earth in Infrared to help people study the clouds. For example they can see different layers of clouds with different temperatures. On NASA's website you can see a picture of Earth with darker warmer colored clouds closer to the Ocean and whiter clouds inland and close to the arctic. The colors you see with visible light also are made up infrared light as well. In one of their pictures you see a tree and waves reflecting off the grass one wave is visible light, which is why we can see that the grass is green, and the other is infrared light. When you take a picture of the grass and the trees with an infrared camera or camera lens, you see that the grass is mainly red which means it is either reflecting or giving off the infrared waves hitting it. This would explain why in the video they get better pictures when it's a bright sunny day because with more of the sun's rays exposed to the Earth there is a better chance that the Infrared waves will hit the plants, and reflect off different surfaces. Also some of the infrared waves will make the objects hotter that it is reflecting against also helping the camera to detect the infrared waves. Links to websites used: http://science.hq.nasa.gov/kids/imagers/ems/infrared.html http://www.mapoflife.org/topics/topic_311_Infrared-detection-in-animals/
    1 point
  47. Awesome blog post and exploration into the world of fluids, Thermo, and chem! I love it!!!
    1 point
  48. due to my procrastinativity, i now have to due all ten posts in one night. its getting quite bland. i feel like talking about computer screens, as it is what i have been staring at for the last hour. so i shall. most screens are lcd, or liquid crystal display. i dont really know why crystals are involved, but it makes me sound like i know what im talking about. in an lcd screen, there are hundreds and sometimes thousands of small boxes called pixels that make up an image. Typically, each pixel is composed of three sections, each for one of three of the primary colors. as you probably know, the primary colors are all you need to make any color out there, however there are two different sets of primary colors, to be used with different applications. why? one set is the additive primarys and the other is the subtractive primarys. in second grade art class, the primary colors were red, blue, and yellow; the subtractive primarys. these were used because paints and inks and such use subtractive color blending, meaning they absorb, or subtract out some wavelengths of light that hit them, the rest reflecting into your eyes as a specific color. each color subtracts a different wavelength from the original white and reflects only one wavelength, and by blending them you can subtract just the right amount of each from white for your desired color. for computer screens, however, (also projectors, ipods, anything that emits light to create colors), the additive primaries are used, being red, blue, and green, one for each section of pixel in an lcd screen. these are different because with a pixel, colors are created additively, or shining just the right ammount of each wavelength from the different color sections, adding just the right ammount of each for your intended color. for example, you see yellow on a screen because red and green light is hitting your retina, activating some green receptors and some red receptors, which your brain recognises as yellow because it is close to the middle of these two wavelengths. also, white light can only be made with additive primaries, as you add all the wavelengths while black light can only be made by subtractive primaries, when you subtract all the wavelenghts from the original white. doesnt this mean computer screens cant create black? they do so by not adding any color, relying on the background of the screen to absorb light that hits it, so actually, every pixel displaying this text is actually every pixel thats not displaying this text. mind. blown.
    1 point
  49. This just in!!! A young physicist of only 17 years old has just calculated the acceleration due to gravity on planet earth. In Irondequoit high school in Rochester New York a group of mere students proved the age old physics fact. Blind faith couldn’t satiate their thirst for knowledge. Armed with a ball, tape measurer, and stop watch these physics fighters set out with a mission: find gravity’s acceleration. Excuse me, I’m receiving their procedure now……It looks as if they had one person start with the ball at a fixed point and then the same person let go of the ball and measured the time it took for the ball to go from the point to the floor. This was done with a stop watch. They repeated this procedure three times. Knowing that the initial velocity was 0 they then proceeded to calculate the acceleration due to gravity using the formula d= vit+ 1/2at^2. This came out to be 13.29 m/s^2. There was a bit of error in their calculation due to the equipment they possessed. They also calculated their percent error and found that it was 35.474 percent. This was most likely due to the variation in their three measurements. Regardless of the variation this was a great discovery in Mr. Fullerton’s class as well as a great confirmation in the world of physics -Jamie D
    1 point
  50. I just did the ruler under the newspaper thing Mr. Fullerton showed us in class for my family and it worked! I was so proud of myself
    1 point
×
×
  • Create New...