Value Definition and 1000 Threads

  1. A

    Why is the expectation value of the commutator not zero in method 1?

    I'm trying to extract the expected value of a |+45> polarized photon in the HV- base. I do it in two ways, one is correct and the other I get wrong answer. What am I doing wrong in the first method that is wrong? method 1 method 2 thanks in advance
  2. Kostik

    I Does the value of the action S have classical significance?

    We obtain equations of motion by solving the Euler-Lagrange equations; along this path the action ##S## is an extremum. We are usually interested in the path ##x(t)## (in one dimension) connecting ##x(0)=x_0## and ##x(T)=x_1##. But does the numerical (extremal) value of the resulting action have...
  3. MichPod

    I What is the value of "delayed choice" experiments?

    What is the value of "delayed choice" experiments? Disclaimer: I do realize that nearly any experiment deserves to be performed even to make sure the QM theory predicts the results of such experiment right. So I have no objections to the work of people which implemented these sorts of...
  4. Mehmood_Yasir

    I Conditional Expectation Value of Poisson Arrival in Fixed T

    Assume a Poisson process with rate ##\lambda##. Let ##T_{1}##,##T_{2}##,##T_{3}##,... be the time until the ##1^{st}, 2^{nd}, 3^{rd}##,...(so on) arrivals following exponential distribution. If I consider the fixed time interval ##[0-T]##, what is the expectation value of the arrival time...
  5. S

    B How to interpret the integral of the absolute value?

    This is rather basic, and may be a misconception of the notation, however, I can't make the following sum up: The following is given: x_n(t) = 1 -nt , (if 0 <= t <= 1/n) and 0, (if 1/n < t <= 1) However, this part I can't grasp this part in the book: \begin{equation} ||x_n||^2 = \int_0^1...
  6. L

    MHB Proving Matrix Equality Using Singular Value Decomposition

    Hi, I have another question, if A and B are mxn matrices, how do I prove that $AA^T = BB^T$ iff $A = BO$ where $O$ is some orthogonal matrix? I think I need to use a singular value decomposition but I am not sure. Thanks!
  7. P

    MHB Find the value for calculate percentage

    Hi Friends, I have x gross amount a = 1739598, Rate of interest R = 5%, and day difference d = 1. Future cash flow f = 176100 now npv = f/(1+r)^(d/360) i.e. 176100/(1+0.05)^(1/360) = 176076.135095 PA = a - npv i.e. 1739598 - 176076.135095 = 1563521.8649 round off value 1563522 rate CR =...
  8. M

    A What is the value of optical effective electron mass for tin

    What is the value of optical effective electron mass for tin metal (white tin)? What is the value of mean free path for electron of tin metal? At least give me some websites or papers where I can find it?
  9. B

    A R value in electron positron annihilation

    In the calculation of R=σ(e+e-→hadrons)/σ(e+e-→μ+μ-) from BaBar experimental data at a center of mass energy of √s≈10 GeV i obtain R=5. Theoretically I should get a value of R=10/3. I know it has something to do with the resonances of ϒ mesons shown in the plot attached, but I don't know how to...
  10. Grands

    Which are the best car brands considered value for money?

    In your opinion which company makes the best quality car considering the value for money? Which company uses the best products inside the cars? In my opinion good cars are Audi and Mercedes-Benz.
  11. W

    Expected value of Poison's ratio for a material

    Hello all Currently struggle with a question from one of my assignments concerning poisons ratio . The notes given to me are vague and before i start trundling through the internet i was wondering if anyone could explain it ?
  12. maistral

    A Integral of Dirac function from 0 to a.... value

    Hi. So I'm trying to use Laplace transforms in inverting a particular s-function via the convolution formula. I ended up with this terrifying-looking thing: So distributing, I ended up with: Evaluating the second integral poses no problem for me (although I think the integration will...
  13. Hawksteinman

    Imaginary value for magnetic field?

    [Mod Note: Thread moved from Classical Physics, hence no formatting template] So today we performed an experiment to measure the Earth's magnetic field in three dimensions. For one of the dimensions we got 6.6x10^-5 i We were wondering if an imaginary magnetic field was possible and what it...
  14. A

    I End Point Energy and Q value in beta decay

    I know that Q value of a reaction is the difference between total initial mass-energy and total final mass-energy of all the products. Then shouldn't be this also the maximum kinetic energy and hence endpoint energy of an electron in beta decay. But what I have read endpoint energy ##E_0 = Q +...
  15. TheBigDig

    Expectation value of mean momentum from ground state energy

    1. The problem statement Consider a particle of mass m under the action of the one-dimensional harmonic oscillator potential. The Hamiltonian is given by H = \frac{p^2}{2m} + \frac{m \omega ^2 x^2}{2} Knowing that the ground state of the particle at a certain instant is described by the wave...
  16. L

    I Critical value of homoclinic bifurcation

    Hello, I hope to find some help. I have equation: and I need to find the value of parameter A at which the homoclinic bifurcation occurs. I know, that in this case A=-0.34, but I solution, how to find it. Can you help me, what numerical method I should use to find A? Thank you very much.
  17. S

    Value of Education (and academic research) in Physics

    We have already seen topics on this forums discussing Physics degree as education and not job training, and that some physics graduates do get jobs but not necessarily as physicists, and that physics majors need to take a selection of practical courses to become marketable; and that internships...
  18. M

    MHB Why Are There No Real Solutions to the Equation \( |x^2 + 4x| = -12 \)?

    Explain why there are no real numbers that satisfy the equation $$|x^2 + 4x| = - 12$$ How is this done algebraically?
  19. M

    MHB Absolute Value Definition....3

    Use the algebraic definition of absolute value to rewrite the expression below in a form that does not contain absolute value.
  20. M

    MHB Absolute Value Definition....2

    Use the algebraic definition of absolute value to rewrite the expression below in a form that does not contain absolute value.
  21. M

    MHB Absolute Value Definition....1

    Use the algebraic definition of absolute value to rewrite the expression below in a form that does not contain absolute value.
  22. MCTachyon

    Net calorific value (CV) per kmol of an fuel/air mix

    Homework Statement [/B] A fuel gas consists of 75% butane (C4H10), 10% propane (C3H8) and 15% butene (C4H8) by volume. It is to be fed to the combustion chamber in 10% excess air at 25°C, where it is completely burnt to carbon dioxide and water. The flue gases produced are to be used to...
  23. T

    A Free Simulator Software for Vacuum Field BVPs | Tom

    Hi, I am interested in simulating the vacuum field equations, but solving a full boundary value problem rather than the initial value problem. i.e. I might have boundary conditions in all spatial and temporal extents/extremes, rather than just an initial 3D surface. Does anyone know any free...
  24. A

    MHB Find value of X in this equation

    Hi, everyone. Can someone guide me in finding the value of x in this equation? I have left calculus for a very long time and I came across this question and wanted to try but I have forgotten a lot of things. f(x)=5+2x and g(x)=2^x Find the possible value of x such that f'g(x)=3/2
  25. R

    Why does my method for calculating this value from...?

    Homework Statement So I have an equilateral triangle of side(s) = 3x10^-2 m Im trying to find the value of the distance from a point directly in the middle of the triangle, to the middle of one side. Homework EquationsThe Attempt at a Solution What I wanted to do was, cut the triangle in...
  26. R

    MHB If g(x) =(kx-p)/(2) , g(7) = 8 , g(5) = 5 then find the value of x and g(x)

    1) If g(x) = \frac{kx-p}{2} , g(7) = 8 , g(5) = 5 then find the value of x and g(x) . 2 )Show that f : N \implies N and f(x) = x+1 is onto function .
  27. karush

    MHB 30 Calculate the book value per share

    $\text{$32$}$ $\text{Newmarket Industries currently has $2,000$ shares of common stock outstanding. }$ $\text{The Firm has assets of $\$200,000$ and total liabilities including preferred stock of $\$75.000$.}$ $\text{Calculate the book value per share of Newmarket common stock}$...
  28. Y

    I Expectation value of energy in TISE

    If Eψ = Hψ, then why is expected energy ∫ψ*Hψ dx? It makes more sense if I see the ψ on the right side of H as the ψ in ∫Q(ψ*ψ) dx, where Q is some quantity we want to measure the expectation of. But if true, then since H is defined as (h2/2m) (d2/dx) + V, then what does it mean to calculate...
  29. D

    Probability that two measurements have the same true value

    Homework Statement I am in a lab course studying Brownian motion. I have gathered data for for movement in two dimensions. I currently have a fairly large data set for ∆x and ∆y and have taken the mean and standard deviation of each. The lab asks what is the probability that these two sets of...
  30. M

    Inverse Square Law with Half Value Layers for X-Rays

    Hello all, I have posted on Physics Forums a few times in the past, but mostly for help with my old physics classes and not anything in the real world. Part of my work involves radiography, but it is generally done in a field environment where we just shut down large sections of land to safely...
  31. M

    Adjusted present value, finance, economics

    Did not find any "place" for this question, but hopefully someone will be able to give me some help with this. corporate tax: Tc= 25% return on debt: rD=4% return on assets = rA= 10% Debt as amount of total value: D/V = 0.6 Equity as amount of total value = E/V = 0.4 A perptual cashflow before...
  32. N

    MHB How Much Should Mattos Oil Deposit Semiannually to Pay Off Their Debt?

    In 6 years, Mattos Oil Refining Company wants to pay off a $50,000 debt in one lump sum amount. They must set up an account to accumulate the necessary funds to pay off their debt. If the payments are made every 6 months and the fund earns 9.6% compounded semiannually, what is the amount of each...
  33. D

    Maximum mass value possible to fuel a spaceship

    Homework Statement We are given that a spaceship converts mass directly to light (emitted backwards) in order to accelerate. If an energy mc^2 has been converted to light ( from the Earth's reference frame) then what is the final speed of the ship (w.r.t. Earth) if the ship's rest mass is M and...
  34. lfdahl

    MHB Find the maximal value of a^4b+b^4c+c^4a

    Let $a, b, c$ be non-negative real numbers satisfying $a + b + c = 5$. Find the maximal value of $a^4b+b^4c+c^4a$.
  35. A

    I Exact value for every observable in QM?

    Folks - I'm asking a lot of questions lately (hopefully useful not just for me). By chance, reading about quantum states, I referenced Wikipedia (dubious I know), and came across the following phrase (with a citation, that I will check): "Even in quantum theory, however, for every observable...
  36. N

    Algrebra equations -- What is the value of B + O + A + T?

    Homework Statement B + A + T = 17 C + A + T = 25 C + O + A + T = 29 What is the value of B + O + A + T?2. The attempt at a solution O = 4 but how to find the rest?
  37. qspeechc

    I Is an R-Value of 0.93 Considered Strong in Social Sciences?

    Hello everyone. I stumbled across an article in the social sciences that had a correlation coefficient of r=0.93. Being from a maths background and knowing nothing about things like social sciences, psychology, etc., is this r-value in these types of fields considered fairly strong, strong...
  38. I

    Calculate expectation value of entangled 2 state system?

    Homework Statement Homework Equations I know that there are two eigenstates of the operator C: |B> = (1 0) as a column vector with eigenvalue 1 |R> = (0 1) also a column vector with eigenvalue -1 The Attempt at a Solution My work is shown here: If anyone could point me in the right...
  39. M

    Question About Duty Cycle and Average Value of a Square Wave

    Homework Statement [/B] 1. Using the Schematic of a 555 in astable mode from the Wikipedia entry on '555 Timer IC," resistor R1 = 8 kOhms and capacitor C = 3 micro-Farads. Determine the value of R2 so that the output duty cycle is D = 0.7. Note that D is not expressed as a percentage here for...
  40. A

    I Help with an expectation value formula

    Imagine a particle in an equally weighted superposition of being located in three distant regions P, Q, and R, and imagine you stand in region P with a measuring device. The probability of finding the particle there is 1/3. Now imagine a large number N of particles prepared in that same state...
  41. I

    I Finding value of parameters to fit some data

    The problem is the following : I have some measured data's obtained when measuring a physical process. Let's call these : yE,L where E and L are 2 physical parameters of the experiment (an energy and a length). I also know that : $$\frac{y_{E,L}}{\sum_{k=1} ^{k=100} {\epsilon_{E,L} (k * v) *...
  42. S

    Minimal value to be determined

    Homework Statement A and X: 6x1 vectors A = [-0.39; -3.99; 1.01; 0.57; -0.70; -2.81]B: 6x6 symmetrical matrix B = [1.1 -0.2 0.19 -1.03 0.69 -0.47 -0.2 0.17 -0.25 0.43 -0.06 -0.05 0.19 -0.25 0.88 -0.62 -0.21 0.29 -1.03 0.43 -0.62 1.59 -0.3 0.04 0.69 -0.06 -0.21 -0.3 0.97 -0.62 -0.47...
  43. redtree

    B The expectation value of superimposed probability functions

    I apologize for the simplicity of the question (NOT homework). This is a statistical question (not necessarily a quantum mechanical one). If I have an initial probability function with an associated expected value and then a second probability function is superimposed on the initial...
  44. kalpalned

    Absolute value notation removal

    Homework Statement Rewrite |x| < 1 and |x| > 1 by eliminating the absolute value sign Homework Equations |x| < 1 = -1 < x < 1 |x| > 1 = ? The Attempt at a Solution I know that |x| < 1 can be rewritten as -1 < x < 1 but I'm not sure about |x| > 1. Am I right to assume that |x| > 1 = -1 > x > 1?
  45. karush

    MHB 232.q1.2c Double integral with absolute value in integrand

    $\displaystyle \int_{-1}^{1} \int_{-2}^{3}(1-|x|) \,dy\,dx$ ok i was ? about the abs
  46. M

    MHB How Do You Solve the Absolute Value Equation -3|x+5| + 1 = 7|x+5| + 8?

    -3|x+5| + 1 = 7|x+5| + 8 Solution: -3|x+5| – 7|x+5| = 7 -10 |x+5| = 7 |x+5| = -7/10 x+5 = ±(-7/10) x = ±(-7/10) – 5 x₁ = -7/10 – 5 x₁ = -57/10 x₂ = 7/10 – 5 x₂ = 2/10 x₂ = 1/5 Correct?
  47. M

    I The truth value of ##P(x)## → ##Q(x)##

    I'm reading Velleman's book titled "How to Prove it" and I'm very confused when I'm reading about conditional statements. I understand that there exists some issue with the conditional connective and I accept that because that's the cost of espousing a truth-functional view. I came here to ask...
  48. J

    Why does my experimental value of g differ greatly?

    Homework Statement Hi, I did an experiment where I launched a soccer ball into projectile motion with my hand and took a video the situation. I uploaded it into the Tracker software to analyze it. The tracker software gave me a x-t graph, a y-t graph, and a y-x graph. From the y-t graph...
  49. Math Amateur

    I Limits and Continuity - Absolute Value Technicality ....

    I am reading Manfred Stoll's Book: "Introduction to Real Analysis" ... and am currently focused on Chapteer 4: Limits and Continuity ... I need some help with an inequality involving absolute values in Example 4.1.2 (a) ... Example 4.1.2 (a) ... reads as follows: In the above text we read ...
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