Physics Definition and 987 Threads

  1. D

    Is the Bohr Model Defined by Equating Coulomb and Centripetal Forces?

    So for this question I just want to make sure that 1. Bohr model is that F_coulomb = F_centripetal? and then get w(r) is called determind? 2. for (b) calculate the frequency, should I use Rydberg formula or what?
  2. I

    Admissions Research experience for physics grad school application

    Hi my name is Idan. I plan to study for a physics Bachelor at Israel, my homeland. although is way too early I'd like to proceed towards higher education as well, particularly in the US. The problem is that in Israel there is no physics internships and research projects offered for students at...
  3. M

    How do you use electrical components adequately?

    The image i provided is a section of microcontroller circuit that i used to interface code in C with the I/O port of the microcontroller, in Proteus. I have realized i was only ever told to learn how to measure the voltage and current across the components, Kirchhoff's rules and all, and...
  4. D

    Programs Studying Physics Abroad: UMich vs Weizmann Institute

    Hello. I have been accepted into a few Graduate programs in physics. I have narrowed down my choices to two: one in America, UMich, and one in Israel, namely the Weizmann institute. There is an important distinction between the two programs. In America, it is a PhD program, which from what I...
  5. Jamestein Newton

    Can one do mathematical physics and theoretical physics at the same time?

    I finished my 1st-year physics, took analysis, linear algebra, mathematical logic, classical mechanics, quantum mechanics(I was exempted from intro phy and took some 3rd-year physics courses) I internal transferred to pure maths. The reason is that the curriculum of the physics programme in our...
  6. kevshabar Reference

    I Skateboarding Physics: Force of Landing from 10ft Roof

    Which scenario would exert the most force on the skateboarders feet upon landing on the ground? Scenario 1: Skateboarder rides skateboard 15 mph off of 10ft building roof Scenario 2: Skateboarder falls directly vertical (0 mph) off of 10ft building roof Assumptions: -- no friction -- maximum...
  7. Jamestein Newton

    Courses Is it necessary for theoretical physics students to take a course in PDE?

    By PDE. The book written by Walter Alexander Strauss perfect described a typical undergraduate PDE course I have in my mind. It should at least include: Laplace equations, waves and diffusions reflection, boundary problems, Fourier series The content of the book I mentioned can also be found...
  8. Anmol Dubey

    Calculating final rotational speed from angular velocity

    I have no idea how to go about this. Any help would be appreciated thanks :) Edit: I converted the 1.5 rev/s to rad/s = 9.4 rad/s
  9. M

    From differential equations to transfer functions

    *** MENTOR NOTE: This thread was moved from another forum to this forum hence no homework template. Summary:: Trying to find transfer functions to design a block diagram on simulink with a PID controller and transfer functions for a water tank system. ----EDIT--- The variables and parameters...
  10. Anmol Dubey

    Finding time taken to stop a skater given mass, velocity and force

    I derived the formula for t but don't know how it works Δt = p/F I got p = mv = 60*8 = 480kgms-1 Δt = 480/120N = 4s Is that correct?
  11. Bernadette

    B Sadi Carnot's Doubts: Exploring Universal Physics

    Hello In his book published in 1830, Sadi Carnot expresses doubts as to the universality of his reasoning on gases. It's on page 89. Is it valid for liquids, solids? And he quotes in the text the freezing of water (increase in volume). What experiments or reflections allowed Rudolf Clausius to...
  12. M

    I Formula for redshift of photon decoupling

    I have come across an old formula from my notes and I have no reference for it but it is using truncated digits in its formula to calculate the redshift for decoupling. The formula is nearly as accurate as the observed data from Planck 2018. So I would like to figure out the derivation of those...
  13. gutelily

    Studying Struggling to teach myself math and physics

    Hey! I want to study physics and math, and eventually, I would like to get a Bachelor in Physics. I quit university about 5 -ish years ago, an Engineering major...I wasn't a good student and don't really remember anything. A couple of years ago I discovered a big interest in Physics and...
  14. Jamestein Newton

    Particle Better Textbooks than Griffiths for Particle Physics 101

    Griffiths "introduction to elementary particles" serves a great introduction as a first course on particle physics for undergraduate students. But what are the possible alternatives of this textbook? Like being more beneficial in the long run, more time-consuming, for aspired students. But it...
  15. P

    Physics homework help needed -- A mass sliding down a ramp with friction

    When mass M is at the position shown, it is sliding down the inclined part of a slide at a speed of 2.19 m/s. The mass stops a distance S2 = 2.1 m along the level part of the slide. The distance S1 = 1.18 m and the angle θ = 28.10°. Calculate the coefficient of kinetic friction for the mass on...
  16. N

    Solving Kirchoff's Laws: Are My Answers Correct?

    Does anyone know how to do part (a). I labelled the current through R1 I1, I4 through R4, I3 through R3, I2 through R2, and I5 through the 3ohm resistor. I used Kirchoff’s Laws to make the equations I1 + I4 = 8, 2I1 + 32I3 - 14I4 = 30, and I1 + I3 - I4 = 0. I solved these equations by subbing...
  17. .Scott

    Examining Semantics in Physics Discussions

    I suggest we be way more alert and expert when working arguments that are based substantially on semantics. A recently locked thread (still considered "hot" at the moment) presented a lively debate on the term "path" as applied to photons. In a few cases, the passive tense was used: "It's...
  18. mcastillo356

    Foundations On how to best introduce the concept of differential in Physics

    Hi, PF Here is the text I've taken a look at file:///C:/Users/usuario/Desktop/2001_JMT_Girep.pdf And the article I'm looking for: Artigue M. and Viennot L. Some aspects of students' conceptions and difficulties about differentials, Misconceptions and Edu. Strategies in Sci&Math. Cornell...
  19. P

    Acceleration of Mass m: Problem Solving

    The problem that i am facing has to do with acceleration. The problem states that we have two balls with the same mass m that stands on two different tables. Between these balls are a wire with the length 2l, which i assume means 2 * l, where l is a value i choose. In the middle of the wire (x =...
  20. robertphy

    Writing a Physics laboratory worksheet, Inspired by Inquiry

    Hi, the task for me is writing a worksheet about Physics experiments in the classroom with a strong emphasis on Inquiry Methods. If you have any suggestion about it (web, courses, people in the field), I'd be very grateful to hear from you. In the meantime, have a safe day.
  21. elad katzir

    Studying What math tools are especially important for physics majors?

    hi all! I'm a first-year second-semester physics major, problem is I'm very weak at math, often not getting questions right just because I get stuck with the mathematics part. this affects me in both mechanics and electricity what are the most important math subject and tools needed for physics...
  22. VVS2000

    Drawing physics Diagrams with online software

    Hello everyone, does anyone know any online websites/software to draw detailed physics diagrams, Like the ones we see in textbooks and research papers. I wanted to draw detailed ray diagram of a lens with mentioning all the angles and refracted rays which is supposed to depict a certain...
  23. H

    KE of photo-electron and nominal interest rate

    Einstein's formula for kinetic energy of a photo electron is $$ KE = h\nu - \phi$$ $$ h\nu = KE + \phi$$ Which basically says whatever energy you provide through radiation, a part of it will be used (but I would like to say 'wasted') in overcoming the work-function (that is in cajoling that...
  24. E

    A The Factorization Theorem in Particle Physics

    I have been tasked with calculating amplitudes of a B meson decaying to a photon and lepton/lepton anti-neutrino pair ,upto one loop and have pretty much never seen this thing before. I will ask my questions along the way as I describe what I am doing. This factorization theorem seems to go thus...
  25. e2m2a

    Creating Physics Simulations in Geogebra

    Does anyone know where one can find complete documentation on how to create physics simulations using Geogebra. I have searched everywhere on the internet and there really isn't any books or complete tutorials on the subject.
  26. L

    Calculating the Radius of a Hot Air Balloon to Withstand a Load of 300 kg

    The result is supposed to be 12,2 m but every time I get 8,016 m... I used for example this formula >r=m/[(density of air-density of hot air)*(4/3)*pi] For density I used > rho=(p*M)/(R*T) Am I forgetting something? Thanks in advance.
  27. S

    Looking for a book with an Overview of Nuclear and Particle Physics

    Hi, I am doing my PHD in Nuclear/Particle Physics and I am getting all of the information I am using from papers, which are very specific. I feel like I am lacking general knowledge, which is likely to be tested in the defense. Do you know any book where I can get a better overview on Nuclear...
  28. Kalebh03

    Schools Choosing a College for a Bachelor's in Physics: NC State vs. UNC Chapel Hill

    I need help in deciding on a college to attend for a bachelor's in physics. I live in North Carolina, and I got accepted into the following schools: Appalachian State University Georgia Tech NC State The Ohio State University Illinois Urbana-Champaign University of Maryland College Park UNC...
  29. A

    I Understanding the physics of a bosun's chair and mechanical advantage

    I had a homework question recently where I had gotten a bosun chair question wrong. It is the exact question found in this youtube video (with the values changed). I am struggling to understand the way 2T is arrived at here (though I do understand this is an example of mechanical advantage)...
  30. Vividly

    Newton’s Principia of Mathematics

    Summary:: What kind of geometry/Math do I need to understand to read this book? Hey people! I would like to know what kind of geometry and/or math would I need to understand this book. I skimmed through it( The translated version by Florian Cajori) and seen that it gets technical with shapes.
  31. R

    Physics Is getting a Master's degree in physics worth it?

    Is getting a masters degree in physics worth it or is anything short of a PhD at the same level as a bachelors when it comes to job types and prospects?
  32. kaiiliana

    Changing capacitance effect on ripple in full rectification circuit

    [Mentor Note -- thread moved to the schoolwork forums] Hi. So I'm a Physics HL student in IB and I'm designing a circuit for my Physics IA. (think of it as a lab/project if you're not familiar with IB) I'm required to have an independent variable of 7 dif. values and a dependant variable. For...
  33. ergospherical

    Other Little Physics Books: Find Your Faves & Enjoy Reading!

    There's a number of "small" (in size) paperbacks which I've quite enjoyed reading, e.g. Schroedinger's <100 page statistical thermodynamics lectures, J.W. Leech's classical mechanics text, etc. Books of this sort are very portable and easy to dip into whenever you get a free 15 minutes or so...
  34. EdmundRonald

    Intro Physics Readable paper version of Feynman's Physics textbooks

    Hi, In my old age I've gone back to study physics at college. I own a really old (1976) edition of Feynman's physics textbooks, but the paper has yellowed to the point where I have trouble reading them, the contrast is low even though the print quality is ok. Is there a printing on good...
  35. ergospherical

    Christopher Nolan & Physics: A Look at J. Robert Oppenheimer

    Christopher Nolan really has an affinity for Physics! Here's a shot of Cillian Murphy (of Peaky Blinders fame) posing as the eminent physicist J. Robert Oppenheimer. The film is based on the biography "American Prometheus" and will depict Oppenheimer's contributions toward the development of...
  36. yezia

    Perspectives with an almost-completed BSc. Physics

    Hello everyone! As I was saying in my presentation post, I dropped out of my physics degree very close to graduation - a year ago. I will firstly explain the whole context of my studies/abandon and then provide some of the perspectives I thought about. As an international student in Canada...
  37. OlPhyz

    12 ton frame lowered on plastic --> What Happens?

    Summary:: 12 ton rectangular frame is lowered by a 4 point crane attached to each corner of the frame. Frame will be lowered onto plastic supports, these supports have guiding ramps of 60 degrees to help the operator lower the frame in the correct spot. The frame has 4 feet, one on each corner...
  38. V

    Physics behind the sound of guitars

    (a) When a taut string is plucked with a finger then it starts vibrating with a transverse wave pattern in the string, which causes the air particles in the immediate vicinity of the vibrating string to oscillate. These oscillating air particles will result in a sound wave traveling in 3...
  39. Mousa Kandah

    Admissions Advice for an Engineer seeking a Masters in Physics in Germany

    Hello, I recently Graduated as a Mechanical Engineer from the University of Jordan and I am looking to do a Masters in Physics in Germany obviously I am at a disadvantage when it comes to admission due to my Bachelors, but I am currently fixing that. I am currently taking Courses in Quantum...
  40. TechmoUnity

    B Assistance finding the nuclear energy difference during nuclear fusion

    Hello! I have finished high school quite a few years ago. I did a physics course that went over nuclear fusion and fission, and I quite enjoyed it. However, I unfortunately no longer have those textbooks (I sold them on as many people do). Now I am doing a bit of programming in the field of...
  41. A

    Magnetic field's effect on a charged particle's motion

    I actually have no idea how to begin. Thanks for help 😊
  42. Woomir

    I Why is my magnetic levitation experiment not working?

    [Mentor Note -- Two similar thread starts merged into one] Hey all, I have been working on this project for a while now, which features suspending an object midair through the use of magnetic levitation principles. Cool right? And so I have been researching and trying, even finding ground...
  43. A

    I Rigid body physics (machine learning environment)

    I guess that the reason that objects fall over is that there is nothing to hold it's center of mass. So what I want to do is to work out how fast in Delta intervals it would rotate and fall over.
  44. Frabjous

    Other Declining interest in Physics Today magazine

    I have noticed a declining interest for myself in Physics Today magazine. Am I just getting old and grumpy or is this a more widespread phenomena?
  45. P

    How much time does it take to warm up water?

    Water heater has the effect 2kW and is filled with 2kg water, with a heat capacity of 4,18Kj. The water needs to be warmed from 300K to 400K. How much time does it take for it to warm up? I've tried to solve this, but it seems that i need to know the heat capacity of the water heater, which i...
  46. S

    Studying Advice Needed: Seeking Help with Math & Physics for Engineering Studies

    Hello everyone, I am new here, and I was wondering if someone could provide me with some advice on how I should approach this in a smart way. I basically really need some bigtime advice on the math part of Physics (or in general). I didn't have anyone to really talk with or that'd be able to...
  47. H

    Electrons and their little role in nuclear physics

    In this thread, @haruspex presented a very deliberate point about the role of electrons in a nuclear fission reaction (he might have said or meant something else but I will present my version of it). The problem that we have before us can be stated, as candidly as my linguistic faculty of mind...
  48. VVS2000

    Studying Mastering Physics Problems: Tips and Advice for Solving Challenges

    Hello All! I recently finished my undergrad but to be honest I actually feel like not learning anything. I could ace the tests because I knew the "pattern" of questions that would come but now if I open an EM textbook by griffiths, I am pretty sure I understand the topic but struggle a lot in...
  49. C

    Solid State Which Introductory Solid State Physics Book from Springer is Best?

    I have the opportunity to get a Springer book for free, provided that it is cheaper than 200$. I am considering an introductory one about Solid State Physics, but I have never heard about a valid one from Springer (I know about Kittel, Ashcroft and Simon only). Do you have any suggestion? Thank...
  50. EishaR

    Physics 101 mechanics help -- Bullet fired by a rifle barrel

    a) a= dv/dt = 2(5*10^5)t+2.8*10^5 2(5*10^5)(0)+2.8*10^5=2.8*10^5m/s^2
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