Condition Definition and 587 Threads

  1. M

    Boundary condition at junction of heated rods

    1. 1D heat conduction problem: Two rods, the first of length a , the second of length L-a with respective cross sectional areas A_1 , A_2 and heat conductivities k_1 , k_2 , are joined at one end. There are some boundary conditions on the other ends of the rods, but my question is only...
  2. R

    Uniform convergence of Fourier Series satisfying Lipschitz condition

    Homework Statement f is integrable on the circle and satisfies the Lipschitz condition (Holder condition with a=1). Show that the series converges absolutely (and thus uniformly). i literally spent about 20 hours on this problem today but i just could not figure it out. i have a feeling...
  3. R

    Proving inequality by induction,given a condition

    Homework Statement If x_{1} x_{2} \cdots x_{n}=1 (1) show that x_{1}+x_{2}+\cdots+x_{n} \geq n (2)The Attempt at a Solution I attempted as follows. I started with x_{1} + \frac{1}{x_{1}} \geq 2 , which is an inequality I already know how to prove. Then using Eq.(1) I get x_{1} +...
  4. B

    Heat conduction in bars: varying the boundary condition. Harmonics problem

    Homework Statement A problem with odd harmonics only. Show that the solution of the heat equation du/dt=c2*(d2u)/(dx2), subject to boundary conditions u(0,t)=0 and ux(L,t)=0, and the initial condition u(x,0)=f(x) , is u(x,t)= \sum Bnsin[(\pi/2L)(2n+1)x]e-((c*\pi/2L)*(2n+1))^2 where n...
  5. K

    Finding D2 for a Dielectric Interface with Given Conditions

    Urgent: Boundary Condition querries. Homework Statement Question given: A dielectric interface is described by 4y+3z=12. The side including the origin is free space and its electric flux density, D=ax+3ay+2az (micro) C/m2. On the other side, (Epsilon)r2 = 2. Find D2. Homework Equations...
  6. F

    Picky about initial velocity condition

    In simple kinematic problems, the initial velocity can be zero or some nonzero value. A friend asked me: what makes it zero in some cases and nonzero in some others. Take a rocket in take off. It has acceleration moving upward, from the beginning, but its v_0=0. Instead, if I apply...
  7. M

    Transversality Condition w/ Right End Point Free & Int. Constraints

    Hi, I've been learning about the calculus of variations this term, and we just covered the transversality condition for an optimization problem with the right end point free, as well as the first necessary condition on the augmented Lagrangian for a problem with integral constraints. I'm...
  8. E

    Is continuity a necessary condition for differentiability?

    Hi Is it true that derivative of a function is possible only if it is continuous!
  9. 2

    Solving Initial Value Problem: Interval Defined?

    This question asks to solve the initial value problem and determine the interval in which it is defined. y'=2x/(1+2y) , y(2)=0 and after solving, we get the equation y= -0.5 + \sqrt{x^{2} - 15/4}(discarded the negative squareroot since governed by initial condition). Therefore, the...
  10. A

    Condition for a 2nd order differential eqn to have bounded solutions?

    Suppose I have a 2nd order differential equation a_1y''(x)+a_2y'(x)+a_3y(x)+a_4=0 and two conditions y(0), y'(0). Then is there any theorem which gives us the condition under which the solution y(x) will be bounded? Note that x-range is entire real line. This is a general version of the...
  11. A

    Linear least squares, condition number

    Hi, I am trying to learn some numerical algebra. Now I don't understand the following. I'm finding the solution to the Linear Least Squares problem min||A\lambda-y||_{2}, which turns out to be (1,1). I did this by doing a QR factorization using Givens rotations. with: A= \[...
  12. J

    Was the Early Universe Hot?

    The big bang is defined as the theory that the universe has expanded from a primordial hot and dense initial condition. Was it hot? I would suspect that the initial condition was in fact cold due to the lack of space and therefore movement. The heat happen directly after the bang. Does this seem...
  13. P

    Medical Is it a condition or a genetic defect problem ?

    Is it a condition or a genetic defect problem ?
  14. B

    Shooting method and a shock wave (discontinuity at the inner boundary condition)

    I've done searching on the topic, and I really don't know where else to turn, so here it goes. I hope somebody can point me in the right direction. I've been working on using a shooting method to solve the steady-state spherically symmetric fluid equations for an accreting plasma. Basically, it...
  15. W

    Find length of a string, given a strange condition

    Homework Statement An apple weighs 1.11 N. When you hang it from the end of a long spring of force constant 1.53 N/m and negligible mass, it bounces up and down in SHM. If you stop the bouncing and let the apple swing from side to side through a small angle, the frequency of this simple...
  16. F

    FORTRAN 90 - DVERK? - initial condition solver

    Hi, I am new to FORTRAN and am trying to work with a system of ODE's. Does someone know of a routine like DVERK for solving initial condition problems for FORTRAN 90? In MATLAB I would simply use ODE45. I just need something similar. Thank you!
  17. R

    Using the condition of vector equilibrium

    Homework Statement Using the condition of vector equilibrium, prove that \sum^{2n-1}_{k=0} cos ((k*pi)/n) Where n is an integer. Homework Equations I know that if n equal vectors are at an angle (2*pi)/n Their resultant is zero. The Attempt at a Solution Please first explain...
  18. S

    What Causes a Body to Move in a Straight Line?

    Homework Statement what is/are for a body to move in a straight line? Homework Equations The Attempt at a Solution
  19. S

    Separable Equation with Condition?

    [SOLVED] Separable Equation with Condition? Homework Statement Solve. http://www.mcp-server.com/~lush/shillmud/int3.71.JPG Homework Equations The Attempt at a Solution I'm not sure how to separate this. Also, since the directions consist of only one word, I'm not sure if y(2)=2 is...
  20. M

    Initial condition leads to periodic solution

    Hi, I have a question that asks me to explain how you could know if the initial conditions lead to a periodic solution of an ODE but I have no clue right now. I'd appreciate any help. Thanks edit: The question is a bit obscure because I am not sure if they are asking in general of for the...
  21. O

    MATLAB, eigenvalues and condition number of a symmetric square matrix

    2. Write a MATLAB® function to calculate the condition number of a symmetric square matrix of any size by means of Eigenvalues: § The power method should be used to calculate the Eigenvalues. § The script (function) should give an error message if the matrix is not...
  22. P

    What were the conditions before the big bang?

    I am wondering what were the conditions before the big bang
  23. E

    Diffraction condition and the Fourier transform

    Homework Statement My book uses the following equation to derive the diffraction condition for electromagnetic waves scattering in a crystal lattice: F= \int dV n(\mathbf{r}) \exp \left[i\Delta\mathbf{k}\cdot \mathbf{r} \right] F is the scattering amplitude and n is the electron density. I...
  24. W

    What is the Electric Field Near a Small Hole in a Charged Spherical Shell?

    The question : Consider a thin spherical shell of radius R with a uniform charge density sigma. If a very small piece of this surface were removed, leaving a small hole, what would the electric field be at a point just above/below the hole? Relevent info : the field due to the patch of...
  25. W

    What Conditions Ensure Adiabaticity in a Slowly Varying Harmonic Oscillator?

    suppose that the potential of a harmonic oscilltor is changed slowly i mean, the frequency of the harmonic oscilltor \omega is varying slowly my question is, under what conditions, the particle initially in the ground state follow the potential adiabatically? what conditions \omega(t)...
  26. J

    Proof that PV^gamma is constant in a reversable adiabatic condition.

    I've been working on this proof, and I just can't get it backwards or forwards, so I must be going about it wrong or missing something. I'm on a re-do for the homework, because my first attempt was completely wrong, so here I go with the second. Any guidance would be appreciated. Homework...
  27. EnumaElish

    Medical Psych: mental condition re flow of time

    Is there a known medical/psychological condition or experience that results in a reversal of the flow of time (e.g., from the effect to the cause)?
  28. Q

    Does any lattice or lattice shape has a periodic boundary condition?

    If not, then what are the conditions for us to construct a periodic boundary condition(PBC)? If so, then please help me construct a PBC for the lattice shape in the attachments. I want to ask that what lattice site m's left neighbor is and what lattice site i's down neighbor is.From the...
  29. M

    Condition for finite series: sum of squares finite + ?

    Let u_n be a sequence of positive real number. If \sum_{n=1}^{\infty}u_n^{2} finite + (condition??) then \sum_{n=1}^{\infty}u_n finite. I want to find the condition.Please help me.
  30. N

    What is the boundary condition for a moving solid boundary in a viscous fluid?

    I am confused on the definition of the "no-slip" boundary condition because of two seemingly contradicting definitions. Definition 1: The no-slip condition for viscous fluid states that at a solid boundary, the fluid will have zero velocity relative to the boundary. Definition 2: The fluid...
  31. P

    Boundary-value problems (Neumann condition)

    Hello Looking for basic boundary-value problems with von Neumann conditions, more specific the applied ones to heat transfer or the wave equation. Could anyone recommend some good book that explains in an easy way the von Neumann conditions or has some solved problems related to the von...
  32. R

    Why Is the Complex Conjugate Taken Again in Orthonormality Proof?

    I'm working through a proof of the orthormality condition for a complete set of states and am struggling with one element of it: Consider the eigenstates of the Hamiltonian in the following way: 1: \int\Psi^{*}_{m}H\Psi_{n}dV = E_{n}\int\Psi^{*}_{m}H\Psi_{n}dV and 2...
  33. T

    Apply Normalization condition in QM problem

    a.) Apply Normalization condition for the n=3 Ѱ-solution to find constant B. b.) Find <x> c.) Find <p> d.) Calculate probability that particle of mass m is located between 0 and a/2. Given: Ѱn(subscript)(x) = Bcos(n*pi/a)x Solution to ∞ square well from -a/2 to a/2 (Width "a"...
  34. Gib Z

    Prove Equality given a condition

    Homework Statement If a+b+c = 0, show that (2a-b)^3 + (2b-c)^3 + (2c-a)^3 = 3(2a-b)(2b-c)(2c-a)[/tex] Homework Equations None that I really need to state. The Attempt at a Solution Well I've just messed around with it, grinding through the algebra, and nothing seems to work. I...
  35. B

    Condition Monitoring: Sensors Used for Electro-Elements in Space Probes

    what kind of sensors do EEs use for condition monitoring in the electro- elements of an electromechanical system? with a view to the subsystems inside a space probe.
  36. B

    System condition monitoring and maintenance

    hi in my engineering design class I've been set a short (1000 word) project on the ulysses space probe or more specifically system condition monitoring and maintenance for the mission. the trouble is, i don't really understand what that involves. can anyone enlighten me or direct me to some...
  37. Z

    What Condition Determines Eigenket of A?

    Homework Statement Suppose that |\alpha> and |\beta> are eigenkets(eigenfunctions) of a hermitian operator A. Under what condition can we conclude that |\alpha> + |\beta> is also an eigenket of A? Homework Equations It's quite basic, I don't think any addtional equations are needed except...
  38. M

    How do I specify boundary conditions in Femlab for a circular system?

    Does anybody know how to put BC at the center of a circle.
  39. S

    How Are Monotone Sequence Conditions and Least Upper Bound Property Equivalent?

    Prove that the monotone sequence condition is equivalent to the least upper bound theory. I can't seem to get around how to prove that the two are equivalent. (it seems trivial).
  40. M

    Condition for inflation presented by Liddle

    I can't understand the condition for inflation that Liddle presents in his book, Cosmological Inflation and Large-Scale Structure A.Liddle, Pg 51: \frac{d}{dt} \frac{H^{-1}}{a} <0 Because \frac{H^{-1}}{a} is the comoving Hubble length, the condition for inflation is that the comoving Hubble...
  41. D

    I am attempting a condition where Newton and Einstein agree

    On this site http://www.geocities.com/physics_world/mass_paper.pdf It states that the 3 force can be written as... F = M1 x A1 + M2 x A2 Where 1 is the longitudinal component of acceleration and 2 is the transverse component of acceleration. It appears that if there is no...
  42. T

    Spontaneous fission condition of the nucleus

    As we know the spontaneous fission of an odd nucleus to an 2 odd nuclei happens with high probability when (Z^2)/A is greater than or equals 45 The conclusion of this is attached in pdf file with the post using the liquid drop nucleus model to explain the problem The question is here now...
  43. D

    Compute Condition Number of Matrix A

    Homework Statement Compute the condition number of the following matrix: | 1 1 | | E -E | where E<<l [SIZE="1"]infinity norm. Homework Equations l [SIZE="1"]infinity norm: ||x||[SIZE="1"]infinity = max |x[SIZE="1"]i| where i goes from 1 to n. Condition number: K(A) =...
  44. S

    Physical significance of othogonality condition?

    what is the physical significance of othogonality condition? or what is meant when we say that two eigen states are orthogonal?
  45. Math Is Hard

    Is Leaving an Empty if Statement in a Recursive Function Bad Programming Style?

    I just finished writing a little recursive function in C++ and when my stopping condition is reached, I need it to do nothing. So the if statement looks funny: if (the condition is met) { //do nothing } else { call yourself with smaller arguments } It works fine, but I feel uneasy...
  46. K

    Condition of a vector field F being conservative is curl F = 0,

    When we say condition of a vector field F being conservative is curl F=0,does it mean that F=F(r)?.I know normally it does not look so.Please,then site an example where F is not a function of r,but still curl F=0.
  47. B

    What are the condition of agency in the individual and the State?

    What are the condition of agency in the individual and the State? Can someone tell me what the question is asking? I can't quite get what agency means... and condition of agency... any insight will be greatly appreciated.
  48. P

    Solving a Differential Equation with an Initial Condition of y(1) = 1

    I am asked to solve this DE with the initial condition of y(1) = 1. (x+y)^2dx + (2xy + x^2-1)dy = 0 So, after working the problem out, I came to this as an answer: F(x,y)=\frac{1}{3}x^3 + x^2y + xy^2-y My question is what do I do with the initial condition. I assume that I am just...
  49. S

    Medical Ummm, Do I Have Some Sort Of Condition?

    I'm wondering if I have some sort of medical condition, if there's any term for this... or if it's just something that's fairly common... I haven't really talked to anyone about it, just wondering if anyone knew anything about this. When I was about 9 or 10, every month or so, my mind would...
  50. C

    Independent trials, dependent condition

    A friend gave me this problem; it's been years since I've taken probability, and I'm really rusty. I'm curious how to solve it. Suppose you have a normal pdf with mean mu and stdev sigma that represents the distribution of test scores. What's the probability that two randomly selected...
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