Ap physics 1 khan academy


Start studying AP Physics 1. Khan Academy . We'll do exciting things like throw things off cliffs (far safer on paper than in real life) and see how high a ball will fly in the air. Sean is based in Boise, Idaho, and is a Khan Academy physics fellow, creating awesome new exercises and articles for AP®︎ Physics. (khan academy The Physics Aviary AP Physics 1 and 2 Review and Practice Khan Academy AP Physics 1 and 2 Review AP Physics EdX MOOCS - search for AP Physics AP Phys Coursera MOOCS - search for AP Physics Bozeman AP Physics Essentials Videos Bozeman AP Physics 1 Videos Bozeman AP Physics 2 Videos AP Exam Prep - problem sets Learn AP Physics AP Practice Exams AP Physics 1 Review Materials . AP Physics 1 review of Energy and Work. Calendar. khan academy, learn, videos, lectures, practice, exercises, skills Words count: 8 Length: 66 characters keyword phrases count : 7 The keywords is too short! [ To optimize the meta keywords, Use this SEO Meta Keywords Optimizer] DeSopo's AP Physics - References - This website is for AP physics students at Lakewood High School to update notes and obtain references and access to lab materials Lakewood High School AP Physics 1 and 2 khan academy, learn, videos, lectures, practice, exercises, skills Words count: 8 Length: 66 characters keyword phrases count : 7 The keywords is too short! [ To optimize the meta keywords, Use this SEO Meta Keywords Optimizer] AP Physics C:Mechanics: The Calculus based mechanics part of physics. Then after that I'll be studying all of the Physics, and if somehow I have the time and will to do it I will study chemistry. Learn AP Physics - Videos, practice problems, and daily emailed practice problem Khan Academy - Videos that follow AP 1 Curriculum Powered by Create your own unique website with customizable templates. The questions are way too easy and are not at all comparable to AP questions. ALHS AP Physics 1‎ > ‎2 - Dynamics (Newton's Laws)‎ > ‎ Newton's Laws (Week 13) Quiz Review Page Static Equilibrium and Trig Practice Problems (with answers): Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a 501(c)(3) nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. , explanation, justification, etc. He’s also a former mechanical engineer. Videos for AP Physics C Follow. Meet one of our writers for AP® Physics, Sean. Online resources to help you learn AP Physics. The Watch video lessons from Khan Academy. We cover a massive number of topics, including K-12 math, science topics such as biology, chemistry, and physics, and even the Take a look at my AP Physics 1 Multiple Choice problems from the 1998 AP Physics C Exam. Intro Physics Best AP Physics 1/2 a textbook so I can prepare myself for next year's AP Physics 1/2 class and so I can do well on the AP test. In this video David quickly reviews the momentum and impulse topics on the AP Physics 1 exam and solves an example problem for each concept. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere. I definatley recommend watching their stuff. AP Physics 1 review of Centripetal Forces. I created my account 2 years ago, and I don’t use Khan Academy as much now, but over the course of those 2 years, I’ve finished algebra 1, geometry, algebra 2, trigonometry, precalculus, AP Calculus AB, AP Calculus BC, and I’m halfway done with multivariable calculus. www. Students cultivate their understanding of Physics through inquiry-based investigations as they explore topics such as Newtonian mechanics (including rotational motion); work, energy, and power; mechanical waves and sound; and introductory, simple circuits. Each question is followed by the targeted learning objective(s) from the curriculum The Ultimate List of AP Physics 1 & 2 Tips In order for you to score a 4 or 5 on the AP Physics exam (1 or 2), it is important for you to follow the tips outlined below. AP®︎ Physics 1 Science & engineering partners. 5,438 views; 6 months ago. Scale of the Universe http://htwins. Another way to let the Khan Academy developers know is to up vote all the posts in this thread. org y *. Review of the Mechanical Waves topics covered in the AP Physics 1 curriculum. The AP Physics B Lessons with Ms. ga. Isaac Newton is often considered one of the most influential scientists of all time, and his contributions to physics are Physics Test Prep such as that from Khan Academy, a small button in the lower right corner of the media control bar allows the content to be shown full screen AP Physics 1 Help » Newtonian Mechanics » Forces » Specific Forces » Force of Friction Example Question #1 : Force Of Friction A block of wood with mass 1kg is clamped to a vertical board with a force of 10N. Our Windows app is the best way to view Khan Academy’s complete library of over 6000 videos on your Windows device. AP Physics 1 Review. 4A Generate and interpret graphs and charts describing different types of motion including the use of real-time technology such as motion Video introduction to rotational dynamics and moment of inertia for AP Physics students. AP Physics 1 PDF . About Transcript. Loved the class, and if you are good at math and have the choice of taking AP Physics 1 or C:Mechanics, take the higher level course. Meet one of our writers for AP®︎ Physics, Sean. Bigler This is a set of class notes for AP Physics 1: Algebra-Based. Sign in now to see your channels and recommendations! Sign in. A physics teacher for seven years, Sean has taught AP¨_ Physics 1, AP¨_ Physics C, and Conceptual Physics. 3 MB) for test-taking tips and more sample questions. Our mission is to provide a free, world-class education to anyone, anywhere. 0 · Reply · Share on Facebook Replies to: AP Physics Teacher Doesn't Teach AP Physics 1 A. The song of AP Physics 1 review of 2D motion and vectors | Physics | Khan Academy is just for review only. Si estás detrás de un filtro de páginas web, por favor asegúrate de que los dominios *. Twu's AP Physics B students take it as their first physics course. A physics teacher for seven years, Sean has taught AP®︎ Physics 1, AP®︎ Physics C, and Conceptual Physics. ACT 34. Let's explore the ideas of displacement, velocity, and acceleration. Get details and read reviews about Review for AP Physics 1 exam, an online course from Khan Academy taught by Aprenda Matemática, Artes, Programação de Computadores, Economia, Física, Química, Biologia, Medicina, Finanças, História e muito mais, gratuitamente. A physics teacher for seven years, Sean has taught AP®︎ Physics 1, AP®︎ Physics C, and Conceptual Physics. AP Physics 1 Review of Charge and Circuit | Physics | Khan Academy By: Khan Academy. physicsclassroom. This hardcopy is provided so that you can fully participate in class discussions without having to worry about writing everything down. Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. org. You can also check out Khan Academy for AP Physics 1 videos. The magnitude of the centripetal acceleration is related to the tangential speed and angular velocity as follows; Centripetal force A centripetal force (from Latin centrum "center" and petere "to seek") is a force that makes a body follow a curved path. Can one perform well on the SAT Physics Subject Test solely by watching Khan Academy's physics playlist? Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere. Physics on Khan Academy: Physics is the study of the basic In this video David quickly explains each concept behind Forces and Newton's Laws and does a sample problem for each concept. This is the currently selected Click on any of the following links to find what you are looking for. lim1 April 09, 2017 20:48 My name is Lisa Krueger and I am a Khan Academy Ambassador teaching in Chicago. A physics teacher for seven years, Sean has taught AP® Physics 1, AP® Physics C, and Conceptual Physics Studying for the AP Physics 1 exam? Watch and practice with these materials Review for AP Physics 1 exam A brief introduction to physics To get the most out of physics, you'll need a solid understanding of algebra and a basic In this video David rapidly explains all the concepts in 1D motion and also AP Physics 1 review of Forces and Newton's Laws. Jeśli widzisz tę wiadomość oznacza to, że mamy problemy z załadowaniem zewnętrznych materiałów na naszej stronie internetowej. yongwoo. Go to your local book store and purchase an AP Physics 1 book. If you really love this song "AP Physics 1 review of 2D motion and vectors | Physics | Khan Academy", please buy the original song to support author or singer of this song. HeÕs also a former mechanical engineer. This Part 1 rerun is based on learner demand! 2016 AP Physics 1 exam -- my solutions I enjoyed writing my solutions to the 2016 AP Physics 1 free response questions. Please let me know if you have any further questions, comments, or suggestions. AP 1-D Kinematics. Our interactive practice AP Physics 1 Equations to Memorize Dolores Gende's Tips and Strategies for the AP Physics 1 exam Mr. but they'll only cover the Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. *Both Khan Academy and Flipping Physics have a series of review videos. Anderson's AP Physics 1 Video Tutorials, Excellent Resources Paul Andersen has created hundreds of science videos that have been viewed millions of times by learners around the world. You Are Here: Home AP Physics 1 AP Physics 1 Additional Topics Rotational Inertia Reading from Khan Academy . P. What is the difference between just the 'physics' course and the AP physics 1,2? I am trying to self study physics to prepare for the engineering course in college. Replies to: Should I take AP Physics 1 or 2 OR AP Physics C? #1. Then check your answers with the Answer Explanations to the Physics Practice Questions (. (4:18) Review of all AP Physics C Mechanics Dimensions (19:20) Review of all AP Physics C Electricity and Magnetism Topics - Video 1 of 2 (17:59) Review of all AP Physics C Electricity and Magnetism Topics - Video 2 of 2 AP Physics B was an Advanced Placement science course equivalent to a year-long introductory college course in physics. 11:20. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. AP®︎ Physics 1. His video essentials for AP Biology, AP Chemistry, AP Environmental Science, and AP Physics 1&2 are aligned to the AP curriculum. The collection contains more than 1000 videos and 2800 Advancing sustainable energy projects within the larger IPS group of companies under the Aga Khan Fund for Economic Develoment in AKDN. Khan Academy allows you to learn almost anything for free. ap physics 1 khan academyMeet one of our writers for AP® Physics, Sean. AP Physics 1 Additional Topics - Rotation. There are less topics covered on the C AP exam, so teachers tend to be able to teach the topics better. AP Physics 1 Review on Khan Academy. AP 2-D Kinematics. org estén desbloqueados. It clearly lays out the course content and learning objectives, describes the exam, and provides sample questions and rubrics. However, make sure to supplement that with a good review book and practice tests to make sure you're also understanding the exam, specific Next year I plan on self studying for several AP tests, and the school I'll be in close proximity to next year doesn't offer AP Physics C. AP Physics 1 : Sound Waves Study concepts, example questions & explanations for AP Physics 1. My teacher actually has us watch Khan Academy videos before he lectures that way we see it explained to us twice and he can move a bit faster through the intro stuff. I've been studying on Khan Academy for the past few weeks, with the help of some friends online I've been passing all the practices pretty easily. g. AP Physics 1 Course and Exam Description—Fall 2017 This is the core document for this course. AP Physics 1 Physics (from Ancient Greek : φυσική (ἐπιστήμη) phusikḗ (epistḗmē) "knowledge of nature", from φύσις phúsis "nature") is the natural science that involves the study of matter and its motion through space and time , along with related concepts such as energy and force . Home Embed All AP Physics 1 Explore AP Physics 1 topics and boost your thinking and writing skills - free textbook supplied. Is there anywhere that I can practice Physics C similar to Khan Academy? Khan Academy has practically zero practice for physics. Did you know pages 162-194 of The AP Physics 1 & 2 Course and Exam Description released by The Collegeboard contains sample Multiple Choice and Free Response Questions and also includes the solutions? The Paragraph-Length Response in AP Physics 1 and 2 (PDF) The Analysis of Experimental Uncertainty in AP Physics 1 and 2 (PDF) Taking AP Physics 2: Algebra-Based can lead to a future in AP Physics_TN; Final Project; Unit 1: Graphing and Physics Review; Unit 2: Forces, Gravitation, and Energy; Unit 3: Energy and Momentum; Unit 4 - Rotational Motion Biology Chemistry Physics Organic Chemistry If you're looking to enter medical school in the United States, Audible Audio Edition MCAT AudioLearn: 0:19 MCAT | Test prep | Khan Academy This collection is being developed for the revised MCAT® exam that will first be administered in April 2015. AP Physics 1 Page 3 AP Physics 1: Algebra-Based Mr. In this video David quickly explains each concept behind Forces and Newton's Laws and does a sample problem for each concept. A PDF will open in a new window. ad by Wikibuy. Keep looking at any notes you've taken from early this year. Introduction to physics. These are optional, but I do recommend them to help review and prepare for the AP Exam in May. Also in AP Physics I this year. HeÕs Khan Academy is a great place to learn the material. Khan Academy is a 501(c)(3) nonprofit organization. AP Students CLOSE. . You can find the questions linked via the official College Board exam site, here . 4% of students who took the AP Physics 2 exam received a grade of 4 or 5. TEKS/SE Curriculum Unit(s) Video Title Rationale (e. National Talent scholarship in ALLEN and AKASH institutes since grade 8. Sign in Help . Get free, Daily Practice Problems! LearnAPphysics tweets a Problem of the Day during the school year, August 15 - June 15. Get details and read reviews about Review for AP Physics 1 exam, an online course from Khan Academy taught by Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere. AP Physics 1 is an algebra-based, introductory college-level physics course. Forces and Newton's laws of motion. HISD Khan Academy Video Correlation / Alignment Page 1 Khan Academy Video Correlation / Alignment . Good luck! I see that Khan Academy has a physics course, and an AP physics 1 and 2. Twu include lectures, physics demonstrations, and problem-solving demonstrations. Syllabus. Contenido principal Para iniciar A physics teacher for seven years, Sean has taught AP¨_ Physics 1, AP¨_ Physics C, and Conceptual Physics. Work AP problem after AP problem after AP problem. ) Ⓡ PHYS. Physics on Khan Academy: Physics is the study of Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Flipping Physics . pdf/247 KB). Chemistry Khan Academy. I have taught AP Physics, Physics, Algebra and Physical Science. Physics challenge) Debate SAT Subject tests 800 in math-II and Physics. Upgrade to a Verified Certificate to get AP Exam Prep +5. Teacher Name: Mr. CC. You can use the exam tips below as you prepare for the AP Physics 1 exam. A physics teacher for seven years, Sean has taught AP®︎ Physics 1, AP®︎ Physics C, and Conceptual Physics. google. Bölüm). Physics . Website #3 - PhET simulation for motion graphs (may need to download) Physics C; Psychology; Khan Academy. Thanks! The request for AP Physics C was added to the user wish list. IIT Robotics Zonal winner - (IIT Mumbai, IIT Delhi, IIT Roekee) College CAD competition (State Level) winner. AP Physics Review Book: I recommend the 5 Steps to a 5 books. Get free, daily practice problems in Physics! AP Physics courses are challenging, but anyone, with sufficient time and practice, can master the material on the College Board's AP Physics exams. Work, Energy and Power Review for AP Physics 1 (8:57) Previous Video. AP Physics 1 Equation Tables AP Physics 1 Equation Tables (Opens in new window) Quantitative Skills in the AP Sciences (Opens in new window) You can use the resources below to prepare for the exam. Is there a possibility that they will be adding AP Physics C any time soon? I know if would be much appreciated. AP Physics Files . CREATE AN ACCOUNT Create Tests & Flashcards. AP YouTube Help BozemanScience AP Chemistry Crash Course Chemistry Ben's Chem Videos Scott Lawson's AP Physics 1 Help » Newtonian Mechanics » Forces » Specific Forces » Force of Friction Example Question #1 : Force Of Friction A block of wood with mass 1kg is clamped to a vertical board with a force of 10N. . but they'll only cover the How do I self-study for AP physics 1 in 4 months? Update Cancel. Website #1 - Khan Academy tutorial on 1-dimensional motion. You can definitely use it to help you learn and review. mohammad@henry. Khan Academy. Play next; Play now 29 Tem 201619 Kas 2017In need of an AP Physics 1 review before the exam next Tuesday? We've got you covered. A Khan Academy é uma organização sem fins lucrativos com a missão de oferecer ensino de qualidade gratuito para qualquer pessoa, em qualquer lugar. com/ Holt Physics https://drive. However, the material is quite extensive enough for one to rely upon it as a sole source of preparation for the AP test. The exercises and videos in the AP Physics are helpful in understanding basic concepts, but I do not feel they in any way adequately prepare students for AP Physics 1 level questions. Choose your answers to the questions and click 'Next' to see the next set of questions. ap physics 1 khan academy AP Physics 1 Course Overview (PDF) AP Physics 1 Course and Exam Description (PDF) AP Physics 1 Equation Tables (PDF) The Paragraph-Length Response in AP Physics 1 and 2 (PDF) The Analysis of Experimental Uncertainty in AP Physics 1 and 2 (PDF) Khan academy ap physics 1 keyword after analyzing the system lists the list of keywords related and the list of websites with related content, in addition you can see which keywords most interested customers on the this website To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry. kasandbox. If Exam Tips. Review of the topics of Work, Energy, Power and Hooke’s Law covered in the AP Physics 1 To get more tips on acing the AP Physics C: Mechanics exam, check out these 5 Steps to Tackling AP Physics C Multiple Choice. framework and the redesigned AP Physics 1 and 2 Exam, and they serve as examples of the types of questions that appear on the exam. Lecture Notes. (khan academy If you want to self-study Physics 1, I would recommend Khan Academy the The College Board or an AP review book (Princeton Review, Barrons, 5 Steps to a 5). Tutorial (Khan Academy): Centripetal acceleration proof. determine the relative motion of an object in one and two dimensions. com/file/d/1ReTC91MO2SF The lessons are designed for students who have never taken any physics course before because about 99% of Ms. The review books tend to make sure you know the basics of everything you’ve learned in class. 4kidsdad Registered User Posts: @hoonie they are free lectures sort of like khan academy The easiest way for me to do this, in my opinion, is to go through the Khan Academy Mathematics section and run through each section I need (Algebra 1 and 2, Geometry, Trigonometry, Precalculus, Calculus). 5, another sitting in Feb. A physics teacher for seven years, Sean has taught AP® Physics 1, AP® Physics C, and Conceptual Physics AP Physics 1 review of 1D motion | Physics | Khan Academy - Duration: 16 minutes. In this Studying for the AP Physics 1 exam? Watch and practice with these materials Let's explore the ideas of displacement, velocity, and acceleration. AP/IB - school doesn't offer. We'll do Let's learn about what a force is and how Newton changed the world's view of How physics is related to math, the other sciences, and the world around us. We cover a massive number of topics, including K-12 math, science topics such as biology, chemistry, and physics, and even the AP® Physics 1: Algebra-Based Questions 1, 4 and 5 are short free-response questions that require about 13 minutes each to answer and are worth 7 points each Visit our Help Center. Physics 1. Physics on Khan Academy: Physics is the study of the basic AP Physics 1 on Khan Academy: Meet one of our writers for AP¨_ Physics, Sean. By the end of this unit students should be able to: determine the direction an object is moving based on their frame of reference. 94% Keyword Research: People who searched khan algebra 1 eoc also searched Instructor: David Wood David has taught Honors Physics, AP Physics, IB Physics and Khan Academy Playlist of videos for review of Biology topics. Khan. AP Physics 1 review of Forces and Newton's Laws. Khan Academy Visit our Help Center. AP Physics 1: Algebra-based and AP Physics 2: Algebra-based are the equivalent of the first and second semesters of an introductory, algebra-based Physics college course. A physics teacher for seven years, Sean has taught AP® Physics 1, AP® Physics C, and Conceptual Physics  Örneğinde Yer Değiştirme · Yer Değiştirme, Hız ve Zaman · 8:39 · Vektörel ve Skaler Büyüklükler · Yer Değiştirme, Hız ve Zaman · 9:18 · İş ve Enerji (1. High school students studied Newtonian mechanics, electricity and magnetism, fluid mechanics, and thermal physics, waves and optics, and atomic and nuclear physics in preparation for a cumulative exam given each May. We cover a massive number of topics, including K-12 math, science topics such as biology, chemistry, and physics, and even the humanities with tutorials on finance and history. Physics C. What You will Need for this One-Month AP Physics C: Mechanics Study Guide. *AP & Advanced Placement Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere. Watch Queue Queue AP Physics 1: Newton's Laws - Chapter Summary and Learning Objectives. School Email Address: amjad. kastatic. Right now I'm trying to complete all of the Math from Algebra 1 and after. In this video David quickly explains each charge and circuit concept and does a sample question for each one. You could also use Khan Academy, an academic website with lecture videos. To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry. I would like the question and videos to tackle more complex AP-type questions. Good luck! Best Answer: Khan Academy will provide you with a good foundation in AP Chem / Physics. 10 CGPA - class 10. Sean is based in Boise, Idaho, and is a Khan Academy physics fellow, creating awesome new exercises and articles for AP¨_ Physics. Si estás viendo este mensaje, significa que estamos teniendo problemas para cargar materiales externos en nuestro sitio. Website #2 - Hyperphysics explanation of 1-dimensional motion. Khan Academy offers videos and practice material for each time period in the APUSH curriculum. 93% - class 11 CBSE. Mastery lessons on Khan Academy are available for K–12 math, grammar, high school biology, AP Calculus AB, AP Calculus BC, AP Physics 1, AP Statistics, AP Government and Politics, and AP Macroeconomics. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Download the SAT Subject Tests Student Guide (. Aprenda Matemática, Artes, Programação de Computadores, Economia, Física, Química, Biologia, Medicina, Finanças, História e muito mais, gratuitamente. AP Physics 1 Help » Electricity and Waves » Electricity » Circuits » Series and Parallel Example Question #1 : Series And Parallel A circuit has a resistor with a resistance of followed by three parallel branches, each holding a resistor with a resistance of . khanacademy. Its direction is always How do I self-study for AP physics 1 in 4 months? Update Cancel. I've tried Khan academy and it helps, but I need more difficult practice problems similar to the AP exam. Follow @learnapphysics on Twitter to be notified of pr AP Physics 1 Equation Tables AP Physics 1 Equation Tables (Opens in new window) Quantitative Skills in the AP Sciences (Opens in new window) The exam is three hours long and has two sections — multiple-choice and free-response. It can also help supplement major topics. net/scale2/ Physics Classroom http://www. Website #3 - PhET simulation for motion graphs (may need to download) Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. k12. I have been teaching in Henry County System for the past three years. I noticed Khan Academy does AP Physics 1 and 2. However, make sure to supplement that with a good review book and practice tests to make sure you're also understanding the exam, specific The exercises and videos in the AP Physics are helpful in understanding basic concepts, but I do not feel they in any way adequately prepare students for AP Physics 1 level questions. us Subjects I Teach: AP Physics, Conceptual Physics, and Physical Science. pdf/6. A secure 2018 AP Physics 1 Exam is available on the AP Course when schools were getting ready to launch AP Physics 1 and AP Physics 2, MAST Academy, FL—This AP Physics 1 Course Overview (PDF) AP Physics 1 Course and Exam Description (PDF) AP Physics 1 Equation Tables (PDF) The Paragraph-Length Response in AP Physics 1 and 2 (PDF) The Analysis of Experimental Uncertainty in AP Physics 1 and 2 (PDF) I see that Khan Academy has a physics course, and an AP physics 1 and 2. In 2015, only 22. Biology Chemistry Physics Organic Chemistry If you're looking to enter medical school in the United States, Audible Audio Edition MCAT AudioLearn: 0:19 MCAT | Test prep | Khan Academy This collection is being developed for the revised MCAT® exam that will first be administered in April 2015. Meet one of our writers for AP®︎ Physics, Sean. Education Online learning Learning Lessons - [Voiceover] Electric Charge is a Best Answer: Khan Academy will provide you with a good foundation in AP Chem / Physics. Mechanical Waves Review for AP Physics 1 (18:43) Previous Video. If you don’t have the right materials, it will be difficult to score well on the AP Physics exam. Mastery lessons on Khan Academy are available for K–12 math, grammar, high school biology, AP Calculus AB, AP Calculus BC, AP Physics 1, AP Statistics, AP Government and Politics, and AP AP Physics 1: Rotational Motion Chapter Exam Instructions. Good AP Physics Review Site . Follow @learnapphysics on Twitter to be notified of pr Khan Academy allows you to learn almost anything for free