Intro Definition and 547 Threads

  1. P

    Does This Material Follow Ohm's Law?

    urgently needed help on intro physics... This is my first time posting on here so I hope someone will answer my questions. Here they are: 1. A scientist testing a material discovers that when a voltage of 10V is placed across a material a current of 10A flows. When a voltage of 20V is...
  2. S

    How Do You Solve This Differential Equation: \( x^3 \frac{dy}{dx} = y \)?

    Homework Statement hey, it's been on my wish list for some time, i have decided to teach my self diffrential equal, rather than waiting to be taught at school, after having some exposure through vibrations and circuits. so i got a book and i started to learn, the question came to be...
  3. L

    Chemistry 1 vs Intro to Chemistry: What's the difference?

    These two courses seem like they would be identical aren't they ? How is chemistry 1 any different at all?
  4. A

    Good resource for intro to wavelets?

    Two friends and myself are going to start doing research with a professor of ours on Haar wavelet transforms. I was curious if there are any texts or any online resources which those of PF would recommend? So far the three of us have completed Engineering Calc I, but the professor feels...
  5. I

    What are the best high school physics books for self-study?

    I CANNOT POST IN THE SCIENCE BOOKS AND MATERIALS SUB FORUM FOR SOME UNKNOWN REASON. Now that that is out of the way, I am in dire need of assistance. I will be taking classical physics I and II this coming school year, and I have very poor physics background. I didn't even take high school...
  6. G

    Best Intro to Quantum Field Theory Article?

    I have pretty good handle on non-relativistic quantum mechanics, but I would like to learn about the Standard Model (Quantum Field Theory). What is the best introductory book and/or introductory article on QFT? Thanks Here are some I've heard of: Articles "[URL Model: An Introduction Authors...
  7. R

    Intro, and a couple of questions

    Hi guys and gals, Stumbled across this forum via google. Quick introduction: I'm not involved in cosmology at all. But I do have a casual interest in it, simply because it inspires me. I'm in my mid 30s, mechanical design engineer, atheist bordering on anti-theist, but that could simply be...
  8. P

    Griffiths intro to electrodynamics Laplace's equation (boundary conditions only)

    Homework Statement A surface at z = 0 is held at potential V (x, y) = V0 cos(qx) sin(qy). Find the potential in the region z > 0. Homework Equations Laplace's equation in Cartesian coordinates The Attempt at a Solution I wrote at least a page of my past 2 attempts at a solution...
  9. M

    Position vector of a moving particle (calc based intro)

    Homework Statement Reviewing for a midterm. I have this problem I can't seem to nail. Want to try it? "The acceleration of a particle moving only in a horizontal xy-plane is given by a=<(3t)i,(4t)j>, where 'a' is in m/s^2 and 't' is in seconds. At t=0, the position vector r=<(20)i,(40)j>...
  10. R

    Recommend Intro Books to Particle Physics?

    Hello everyone- I was wondering if anyone could recommend introductory books on particle physics? I'm looking for something an undergrad could read as if they were taking a beginning course. I've searched Amazon and found tons of college textbooks only I'm not sure which ones are...
  11. R

    Intro to analysis proof first and second derivatives and mean value theorem

    Homework Statement Let f(x) be a twice differentiable function on an interval I. Let f''(x)>0 for all x in I and let f'(c)=0 for some c in I. Prove f(x) is greater than or equal to f(c) for all x in I. Homework Equations Mean value theorem? The Attempt at a Solution f''(x)>0...
  12. S

    What are some affordable introductory neuroscience books?

    I'm looking for an introductory neuroscience book. I only know basic biology so I'm not sure if I'd be ok in reading a textbook (I do have the whole internet though if I come across something unfamiliar). I've seen several books however they seem geared for medical students instead of actual...
  13. D

    How Does Relativity Affect the Perception of Time Between Supernovae?

    [b]1. The star Alpha goes supernova. Then ten years later and 100 light years away, star beta goes supernova. Aliens passing by observes that the explosions occur 120 light years away. According to them, what is the time between the explosions? [b]2. So I think I am supposed to used the...
  14. S

    Finding An Initial Speed, Intro to Physics Question

    A boy tosses a coin straight up to 2.8 m. Suppose the height when the coin leaves his hand is 1.2 m. What was the initial speed of the coin when it left his hand? I'm just confused as to what equation to use. And I don't know whether to assume the acceleration is -9.8 m/s^2. Thanks.
  15. B

    Intro Analysis - Proof - max M

    Homework Statement If S\subsetR is finite and non-empty, then S has a maximum. Can someone look over this? I struggled a bit in my first proof class, which is why I am asking for help, so I really am unsure if this is right at all. Let S={1} So 1\inR such that for all x\inS, 1\geqx So...
  16. B

    Intro Analysis - Real Numbers - Inequality proof

    For 0<x<y, show that x<\sqrt{xy}<1/2(x+y)<y I have no difficulty showing that x<\sqrt{xy} and 1/2(x+y)<y. I am having difficulty with \sqrt{xy}<1/2(x+y). x<y xx<xy x^{2}<xy x<\sqrt{xy} and x<y x+y<y+y x+y<2y 1/2(x+y)<y
  17. 1

    A really low grade on my intro physics final.

    Well, I got a D grade on my intro physics final, which means i got the credits for the course, but my gpa has dropped down a few points. My teacher is not to blame but he sure didn't help either...he has a passion for the subject, but not for teaching. Anyway, I guess i should take it...
  18. 1

    Is the Traditional Education System Hindering Our Understanding of Physics?

    Repeating "Intro. Physics." I am in my late 30's, and I have an exam this Saturday on "intro. physics." What I have found is that I enjoy Physics when I learn at my own pace rather than under the structure and (what I perceive to be) rigid time constraints of the University environment. I find...
  19. S

    Intro Fluid Dynamics homework question

    How much force is necessary to lift a ring, diameter 20mm, made of fine wire, and placed on the surface of water at 20 degrees celsius? All the equations from the chapter: Shearing stress = F/A = Viscosity*(velocity parallel/h) Kinematic Viscosity = viscosity/density Change in pressure =...
  20. L

    What Are the Key Applications of Series Detectors in Computer Engineering?

    I'm taking this class and so far we have learned very basic stuff. The chapters that we learned so far are: 1 binary systems 2 boolean algebra 3 gate level minimization 4 combinational logic 5 synchronous sequential logic we have to write a 5 page paper on "applications of what we...
  21. 1

    Schools Second Chance at Intro College Physics: Can I Make It?

    Hello, I'm in my 30's and haven't been studying algebra, trig, or physics for around 19 years. Well, i just failed my second physics test and I'm pretty bummed out about it. However, I was thinking of taking the same class again next semester, but I'm not sure if i will do any better the second...
  22. B

    What was your favorite intro to biology textbook?

    How did you guys like your intro to bio textbooks? What was your favorite and why?
  23. C

    Looking for good intro books/texts on dynamical systems

    I'm taking a course in dynamical systems and I'm struggling to grasp some of the concepts. The instructor only occasionally reference the textbook I'm using, which is Differential Equations, Dynamical Systems, and An Introduction to Chaos 2nd Ed. (By Hirsch, Smale, and Devaney). I'm looking...
  24. G

    Best Intro to String Theory Review Article?

    What is the best review article, published in a peer-reviewed journal, introducing string theory?
  25. D

    Intro QM: Add a constant to the Potential, Effect on Wave Function?

    Hi, I've got a problem with the following problem. This is 1.8 out of Griffiths QM text, and was previously covered on this forum for another user in https://www.physicsforums.com/showthread.php?t=152775", although that thread doesn't address my problem. 1. Suppose a constant potential...
  26. L

    What is the real point of Intro Physics?

    I'm almost finished with my first years of physics and I've noticed a few things. Granted each school is different but people out there with some more insight can perhaps clarify. 1. Even for an interested student of physics there seems to be far too much material covered over these courses...
  27. R

    Which Books Are Best for Physicists Learning Manifolds and Differential Forms?

    Which book/books are a good intro into manifolds? Maybe a book that is both oriented towards a physicist but also includes rigor. How is this book An Introduction to Manifolds by Loring W. Tu In the preface it says one year of real analysis and a semester of abstract algebra would suffice as a...
  28. X

    Medical Problem from Intro to Health Physics by Cember and Johnson

    Hello guys, can you please help me figure out how to solve this problem. Many thanks! A scanning He–Ne laser that scans at a rate of 10 s−1 emits 5 mW through an aperture of 0.7 cm. If the beam divergence is 5 milliradian, then, for an intrabeamviewing distance of 200 cm, calculate (a) the...
  29. F

    Good calculus based intro physics text book

    I'm not sure if this is the right forum, but I'd like to know: What's a good physics text that uses calculus? I mean, not just uses calculus in the definitions of velocity and acceleration and whatnot, but uses it in almost all the problems? I find my current text, "Fundamentals of Physics" by...
  30. 1

    How Can I Improve My Physics Grade After Failing a Test?

    Today I failed my intro Physics Test...I got 24%. This test is worth 20% of my final overall grade...so I'm really quite bummed out about this. I've been studying hard...I guess it's because I'm in my 30's and haven't been in school doing Physics for around 15 years. Anyway, anyone have...
  31. U

    What is the Velocity and Distance of an Automobile with a Changing Force?

    I have posted a problem below and my attempt could someone please tell me if I am going wrong and where. Thanks An automobile of mass 650 kg is acted on by a net force (F) given by F = 800 - 40.0t, where t is in seconds and F is in Newtons. At t=0, the velocity of the automobile is 5.00m/s...
  32. L

    What are the possible values of g'(a) at a differentiable point (a, g(a))?

    Homework Statement If the functions f and g are defined so that f'(x) = g'(x) for all real numbers x with f(1)=2 and g(1)=3, then the graph of f ad the graph of g: Is the answer that they do not intersect? The other choices are: intersect exactly 1 time intersect no more than 1 time could...
  33. N

    Basic Intro. Analysis Sequence Proof

    Homework Statement Suppose that x0\in (-1,0) and xn=\sqrt{xn-1+1} -1 for n\inN. Prove that xn\uparrow0 as n\rightarrow\infty. the formatting is odd so read outloud, the function for x sub n is "x sub n equals sqrt(x sub (n-1) + 1) -1. If it is still unclear, ask and I can post an image...
  34. J

    Intro to Engr Homework. Simple Physic Problem.

    Homework Statement Assume 50 W of power is used to perform each of the following tasks (one at a time). a. Lifting 1000kg (1 ton) by one meter. b. Lifting 1 g (0.001kg) by one meter. (Hint: What is the potential energy gain by the object?) How long would it take to complete the first...
  35. Y

    EE intro question regarding Voltage and Amps

    Homework Statement http://rsteiger.is-a-geek.com:81/homework%20question.jpg The question for me is merely conceptual. I'm really good at math (not that a lot would be required here) but I don't even know where to start, hence the lack of an attempt. I'm not looking for the answer (I already...
  36. E

    Recommend good intro to PDEs book?

    I'm taking a first course in PDEs this term (I'm a physics student) and we are using "Beginning Partial Differential Equations" by Peter V. O'Neil, which I find almost unreadable. Can anyone recommend a good book appropriate for an introductory PDE course? I have taken a standard ODE and...
  37. I

    How Far Will a Race Car Travel After Running Out of Gas?

    Homework Statement A race car with the weight of 10 000 kg is traveling at 10.0 m/s when it's gas runs out. How far will this race car travel till it reaches an absolute halt? Homework Equations F=ma v2^2-v1^2=2ad The Attempt at a Solution Fn= 490 000N v2^2-v1^2/2d= a and I...
  38. K

    Help Intro Physic problem dealing with Kinetic

    Homework Statement A model rocket is launched straight upward with an initial speed of 46.7 m/s. It accelerates with a constant upward acceleration of 2.16 m/s2 until its engines stop at an altitude of 138 m. What is the maximum height reached by the rocket? How long after lift off does...
  39. LarryS

    Best Intro to QFT Book for Mathematicians?

    Can anybody recommend a good introduction to QFT book? I'm looking for something that just barely classifies as a textbook, with lots of tutorial verbiage between the equations. Thanks in advance.
  40. M

    Courses Advice on intro phys/calc courses

    Hey, does anyone know what I should expect from my 1st year PHYS 111/112 and Math 121/122/Biometrics courses? I have a basic understanding of some calculus concepts (derivatives and functions) and I know a bit more about chem, meaning that my physics knowledge is probably better than my...
  41. M

    Intro Physics problem - 2 oncoming trains, help

    Hey I'm in high school and I need help with this seemingly easy problem. I have 3 constant acceleration equations but I don't know how to use them in conjunction with this problem. A train leaves from Chicago toward Atl going 20 m/s. At the same time another train leaves from Atl going to...
  42. S

    What is the best intro book for Chemistry

    I want to take Chem for college 1 without taking Intro to chem. Which book will most suit my need?
  43. H

    QM Questions: Intro & Two Conceptual Issues

    I'm preparing for an upcoming course in QM by working out of a textbook, and I've encountered a handful of conceptual questions that I'm having trouble answering. I figured it best to ask my questions in a single thread, so as not to clutter the subforum. Also, I chose the general physics...
  44. R

    Quiz question, wondering how to actually solve (intro intro probability)

    Homework Statement so my professor gave us a little quiz today here's a question i was unsure of how to solve. probability of engine damage is 0.15 prob of transmission damage is 0.02 prob of both engine and transmission damage is 0.01 what is the prob that a car comes in the shop with...
  45. Q

    Intro to Chemistry: Find a Short Intro Course For Chem 101

    Hey guys, I am taking chem 101 this fall, but it has been a long time since I took chemistry in high school. I am looking for a good short intro to the topics that are usually covered in a first year chem course. Can anyone recommend any good and relatively short (less that 300 pages)...
  46. T

    Is The Bare Essentials the Best Starter Book for Learning English Grammar?

    What is such a book? I'm looking for easy to read book.
  47. W

    Intro to Integrals: Understanding The Addition Property

    I`m reading on Integrals, and at the introductions author mentions three basic concepts, The Rectangle Property, The Addition Property, and The Comparison Property. I understand what the 1st and 3rd properties mean, and I have a question concerning the 2nd. "The Adittion Property: The area...
  48. K

    Intro to Physics 1: Advice & Motivation for Beginners

    Alright, I'm on the road to be a physicist! This may be the first step towards my career and I'm looking for some advice. So please share me some advice and motivation. I need all the guidance in this course from experts.
  49. malawi_glenn

    What Are the Best Introductory Resources on Conformal Field Theory?

    Hello Anyone got some introductory notes / books on Conformal Field Theory for someone who know Quantum Field Theory at the level of Peskin's book? cheers
  50. D

    Which Book is Best for Learning Fourier Analysis?

    Hi, I am starting in a Ph.D. program in math next fall and the prerequisites for the first-year graduate course sequences included basics of Fourier analysis. The only thing I know about it is that you calculate a projection of a function on a certain infinite dimensional subspace, so I do...
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