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  1. 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
  2. If you wanted to, you can change your name and remove your last name in the settings! Enjoy physics!!
    2 points
  3. 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
  4. Bonus $20K to team BCD for the Kerbal Royal Wedding Painting!
    1 point
  5. That's the richest pauper I've ever heard of...
    1 point
  6. From - https://answers.yahoo.com/question/index?qid=20110917100043AAuhgCE
    1 point
  7. It's basically the same test, though in recent years I have heard several statements that there is more of a focus on calculus-based questions (previously you could do reasonably well on the exam without solid calculus skills).
    1 point
  8. 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
  9. 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
  10. Introduction: We decided to see if cars travelling North down Cooper Road outside of Irondequoit High School were speeding. We set up a timing station at twenty meters from the start to measure the speed of passing cars. Procedure: We chose a starting point on a line on the road, so timers could better see when cars started the measurable distance. When a car passed the starting point, timers at the station began their stopwatch. When the car passed the timer, they stopped their watch. Timers recorded the time it took for the car to travel the distance. Calculation: Conclusion: The average speed was 15.7 m/s, just .1m/s over the speed limit. Our conclusion is that cars travelling on Cooper Road do not often speed, perhaps due to the school zone. If we do this experiment again, there are a few things we can improve on. For one, we had some large distances in time span; this can be remedied by perhaps standardizing the timing system – should the timer start/stop when the front of the car passes through each point, the middle of the car, or the end?
    1 point
  11. Hey Seth, I wish you had my letter to the next years physics student.
    1 point
  12. 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.
    1 point
  13. 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
  14. Seriously hose 22 is great!
    1 point
  15. 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
  16. I wish I could see goats from my backyard... good luck with your music
    1 point
  17. You're really good at guitar Peter! And I agree with your second paragraph, it really will help to view the world differently! Oh & the homework part too!
    1 point
  18. 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.
    1 point
  19. X-country captain, nice Pete.
    1 point
  20. 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...
    1 point
  21. 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
  22. Good Evening Folks, I've received quite a few requests over the past couple months, and especially the past couple days, asking if I knew of an "outline version" of the AP Physics 1 learning objectives, essential knowledge, etc., organized by topic. I already had this created from working on the AP Physics 1 Essentials book as a chapter outline/roadmap correlated to the new AP 1 course, but had never bothered to put it in a user-friendly format to share. Well, until yesterday. Here it is: http://aplusphysics.com/educators/AP1Outline.html/ I understand this may not be the order in which you'd teach the topics, but for me at least, this organization is much easier to wade through and make sense of than the current AP Physics 1 and 2 Framework document (in which I get easily lost in the 200+ pages). Perhaps it will be of use to you as well. Please note that you can drill down by clicking on the triangles to the left of the topics, it's quite a big document if you expand it all out. I'm planning on doing this for AP-2 as well, though I probably won't have a chance to start on it until late July. Make it a great day! Dan Fullerton
    1 point
  23. Hi Mr. Fullerton, Thank you so much for your swift response. However, I am not sure I understand what you mean in: To choose between A or D, look at the function you're using to model the waves and its value at time t=0. With a phase change of 5Pi, you'll have the opposite situation you would have at time t=0. So for a basic cosine function modeled so that the E field has a maximum value at time t=0, at the instant in time where the phase is 5Pi, it would be at a minimum (0) value, so the answer would be A. If you are modeling the wave so that the minimum value is exhibited at time t=0, you would have a maximum magnitude at phase 5Pi. How do you know that the model of a Electromagnetic wave is cosine? Also, how do you know that the mininum vector is at 0(I know this is the only option but is there a way you would know this if the minimum was not given to you)? Thank you so much for taking the time to answer my question!
    1 point
  24. The Hour of Code is simple. Just go to code.org and click the START button. Yes, it is really that simple. There are quite a few tutorials at several different levels and in several different programing languages. But the real ... View the full article
    1 point
  25. Question: Three charges are placed at the corners of an equilateral triangle with sides of length 2.0 m. The three charges at the corners of the triangle at +4.0 X 10^-6 C, +2.0 X 10^-6 C, and -4.0 10^-6 C. Determine the electric potential at the midpoint of each side of the triangle. What I have done so far: So we know that the formula for electric potential is V=kq/r. So we can just use one of the charges to find the voltage. However, the answer differs depending on which of the 2 charges(which vertices you pick) for each charge. Thank you for taking the time to answer my question.
    1 point
  26. Hi, I was wondering how a Faraday cage works. Why is that that electric fields exist outside conductors and even on the surface of conductors but the field is always perpendicular to the surface of the conductor? Also, in relation to this topic, a conductor with an excess of negative charge is in electrostatic equilibrium. Describe the field inside the conductor. What does it mean for it to be in electrostatic equilibrium. Is it just that the electrons are on the surface of the conductor? if so, wouldn't the inside of the conductor be charged positive because a lot of the negative charge is no the surface. Thank you so much for those who take the time to answer my question!
    1 point
  27. You'll do great at ANYTHING you set your mind to, I have no doubt. And thanks so much for your too-kind comments. Made my night, definitely my week, without a doubt the month, and quite possibly my year! Now to go find a tissue, I think a bug just flew into my eye and made it tear up a bit...
    1 point
  28. 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
    1 point
  29. Nice to have you on the team Mir, and I'm happy we have a class together! Hopefully we can help eachother to succeed in this class this year
    1 point
  30. Omg Miranda!!! i hope you do good with chearleading
    1 point
  31. Hi I'm Reed and I go to west irondequoit high school. I will be going into my senior year and I super excited about the fact that I am senior class president for the second year in a row. I am also a dancer I have been dancing for 11 years, I am also the captain of the varsity swim team for the second year in a row. I also love to read books, listen to music, hang with my friends, and learning something new. In high school you are told to take three years of science and the fourth year is optional, you decide if you would like to continue on with science. I had originally planned not to go into a fourth year of science because I am not a science person and I do not do well, however my counselor convinced me otherwise. She told me that many colleges look if you have taken four years of science and they prefer that you continue with science as long as you can. I decided that she was right and I picked physics because i really want to shot a catapult and make bottle rockets. That to me makes science more fun and interesting.
    1 point
  32. Hi Baillie! Wow, that is an excellent reason to take Physics!! This class might push you at times but don't forget that you have a wonderful support system of Mr. Fullerton, Miss Lawson and myself to help you along this crazy journey. Have a great start to the school year!
    1 point
  33. Time travel was inconceivable for Newton and his studies. But in Einstein's universe it has become a possibility. Science fiction about time travel inspired some of today's scientific ideas on the subject. So dreaming about alternate universes is ok no matter what field you study. Time travel to the future is possible, and it has happened. Like FizziksGuy said, astronauts have aged slightly less than we whose feet have stayed on earth. Now whether time travel to the past is possible, that is still debated, given certain physical conditions. Also, the study of time travel can be used to discover whether the universe could have been created itself. Because of research on time travel, some scientist claim to have a prediction on the span of human existence. Considering how much time we have lived on earth, it is remarkable how much we know about the universe.
    1 point
  34. Very expensive but it looks good.
    1 point
  35. 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:
    1 point
  36. NO GO!!!!! Your fuel use is ridiculously high and inefficient. You will waste a ton of money on parts that will just crash back down on Kerbin because you don't have parachutes on them. And you will kill your Kerbal because there is no parachute on his cockpit. Rethink this one before launching.
    1 point
  37. How can you be sure that you will reach Mun orbit? Are you going to circularize your Kerbin orbit first or burn straight for Mun? What Time would the most reasonable launch window be to meet your goals?
    1 point
  38. 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
  39. This is a really good trailer. Although I got into ksp before the trailer, It still really inspired me.
    1 point
  40. First try finding the charge in coulombs, then convert coulombs to electrons. This mini-tutorial may help: http://www.aplusphysics.com/courses/honors/circuits/current.html So, if you use q=It, solve for q in coulombs. Then, convert q (in coulombs) to elementary charges, or electrons, using 1 electron = 1.6*10^-19 C. Does that help?
    1 point
  41. The posters around the halls and in classrooms have gained some traction and have garnered perhaps an increased awareness of the potential for STEM careers- but is it too late? I sometimes wonder if we haven't done enough to build the curiosity and "excitement" for STEM in the levels for where it matters most - in the elementary, middle and junior high levels. Some of the best experiences within science programs have been removed (Science "fairs" or long term projects that allow students to build models, test designs and collaborate with peers - outside of school have been replaced). Content coverage is an issue - instead of building the scientific practices. By the time students are in high school, the discipline silos do little to show the interconnectedness of STEM concepts, and teachers may or may not have access to the network connections that support the burgeoning interest of their students. That issue of content coverage (and even the sequence of courses) also does little to spark interest in STEM - courses become a series of isolated facts to remember.....it would be interesting to take a look at the students that participate in AP science courses - why they take what they take and when they decide to take those courses..... Now don't get me wrong -there are fantastic teachers who, even faced with the issue of coverage, bridge connections for kids and spark interest. They engage their students in complex, challenging problems and promote critical thinking skills that are necessary for success in any STEM path. I don't think that this is an issue where there is one causal factor - parents, teachers, society, higher education institutions, corporations......all need to be a part of the conversations, and then hopefully reach the same conclusion regarding the importance of STEM in order to develop a LASTING plan of action for our educational system. So, the question you pose is a relevant one. We need sustainable partnerships that can bring skill-developing, real-world challenges and problems based opportunities to our students, while supporting the heart of our disciplinary core ideas. We need a coherent, comprehensive K-12 program, where STEM never becomes an afterthought.
    1 point
  42. Hello, hopefully I am posting in the right area. I apologize if not. I am studying the physics iBook "Physics - fundamentals and problem solving" , which is an absolutely amazing book by the way.. i had no idea one could teach through a book with a few videos and get the same results as a full on physics classroom. But anyway, there is a concept I am having trouble grasping. I understand that the force of the gravitational pull is mass times acceleration of gravity but what I'm having trouble with is what we are measuring when we stand on a scale. I was browsing the net and I got onto the Wikipedia site, http://en.wikipedia.org/wiki/Pound_(mass) , where it says that pounds are units of mass in the imperial system we use here in the US. It also goes on to talk about pound-force and pound-mass and that is where It gets me confused. When I step on a scale, is that scale measuring my mass? or my weight here on earth? Pound force would be weight (mass times gravity) and pound mass would just be mass I suspect?it might be a silly question to most, but I've never heard of this. and coincidentally, if one pound is .45359 kilograms, does that mean 1 pound-mass or pound-force equals .45359 kg? When they step on a scale with kilograms, is it measuring their weight or mass? In weight lifting, or on truck scales in kilograms, is that the mass or the weight? Thanks!
    1 point
  43. 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
  44. Three amazing students at Irondequoit High School have made a break through in the study of physics: By only using a stopwatch, a measuring tape, and a ball, the acceleration due to gravity has been calculated in a new and scientific way. Students measured the height from the floor of the classroom to the top of the ceiling with a measuring tape, and got 2.75 Meters. Holding the ball at the top of the ceiling, the three students dropped the ball and started the stopwatch at the same time. They measured that the time the ball took to hit the bottom of the floor was .64 seconds. Also, the initial velocity of the ball was 0 m/s because any object dropped starts with an initial velocity of 0. Using this information, the students calculated for the acceleration to see if it really is 9.81 m/s2 . The Formula : d= viT+ (1/2)(a)(t^2) was taken to figure it out. with the information they had, the converted formula became: 2(2.75 m)/ (.64s)^2 = A . The answer obtained was 13.4m/s^2. Obviously it is not the real accepted value of 9.81, so they had to calculate percent error also. using the formula: (accepted value - actual value)/(accepted value) X100, the answer came out to be that there was a 36.6% error in their experiments. Faults in the experiment were being able to time the stop watch precisley, and measuring an accurate distance from where the ball was dropped , to the ground. Overall, the students at Irondequoit High School have created astounding breakthroughs in calculating acceleration due to gravity.
    1 point
  45. Here's a problem I encountered sometime in the first few weeks of mechanics last semester. Post an answer if you get one, or ideas if you have them. I can provide hints as necessary (diagrams, possibly useful tools, etc.) maybe starting later in the week. At this point I am considering turning these around on a weekly basis, and so I'll probably post a solution Monday, 12/6. If Mr. Fullerton wants to give extra credit for such things, I imagine one would want to have it done before then for extra points. And show all work! Whether by beautiful here or by mailing be the back of a napkin, documenting your thinking is imperative. Suppose a hockey puck sits atop a spherical, frictionless surface of radius R. The puck is then given a very small nudge, just so that it begins moving slightly (this nudge imparts a negligible amount of momentum onto the puck). Through what vertical distance does the puck descend before leaving the surface?
    1 point
  46. Hi Elliot, It does seem too easy! And I understand why you think the answer must be R, because I did too when I first read the problem. Unfortunately, it's not that easy. As the puck slides down the surface of the sphere, it accelerates both out and down. At some point, the out component of the puck's velocity becomes so great that gravity cannot keep it on the sphere. I encourage you to convince yourself of this by rolling a marble off a basketball or some other similar surface. (Rolling adds extra complexity to the problem, but the same principle applies.)
    1 point
  47. not if the object accelerated until it got to 2 m/s but when it reached that point the force would have had to change to a point where it equaled the force of friction. It doesnt say anything about what happend before 2 m/s so you dont have to worry about that
    1 point
  48. well you know 3 could because if you put 3N and 4N at 90 degrees there resultant would be 5N, so if you put the 5N in the opposite direction of the resultant the object would not move. 2 could work too, because if you set it up so that the 3 2N forces were 120 degrees apart, a peice, you would be able to achieve an equilibrium (draw it!) Now that i think about it, the answer is 1. 1 could not have an obtainable equilibrium. When you put the other ones at funky angles you can always achieve an equilibrium. BUT, for number 1, even if you had the 5N force going one way, and the 1N and 3N force ON TOP of eachother heading in the exact opposite direction, you could not add up to the 5N needed to attain an equilibrium. Adding an angle between the forces only reduces the resultant (there is no sinx or cosx value bigger then 1). So to do this problem, the first step would be to see if 2 of the resultants can add up to be greater then or equal to the other resultant in all cases. For number 1, 1N + 3N < 5N, so it would be impossible to have an equilibrium
    1 point
  49. I'm hoping this is the right place to post for Physics C Problems. I thought I heard that people were confused by the billiards web assign so I thought I'd weigh in. To me it seems like the velocities of the cue ball and the 8-ball have been switched on the webassign, but maybe I'm crazy. Also, I only know from experience that perfectly spherical billiard balls that collide perfectly tangentially ricochet off each other at complimentary angles, but the mathematical explanation in the answer packet leaves a bit to be explained for me. Any clarification would be much appreciated!
    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
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