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  1. Hemmer

    Intuition about Stokes flow beween solid walls

    Hi there, I have a question about incompressible Stokes flow in a channel between solid walls (with no-slip boundary conditions at ##y = 0, L_y##). It is my intuition that, if the flow direction is ##x## (periodic), and the direction normal to the walls is ##y##, then there cannot be a net...
  2. Hemmer

    Parallel FORTRAN output varies with addition of arbitrary WRITE statement

    Hi there, I've been puzzling over the following code (which works in serial). It produces radically different answers if the (blank) WRITE(*,*) is included or not. Any help greatly appreciated! eps = 0.0 !$omp parallel do default(none) private(i, j, current_angle, current_energy) &...
  3. Hemmer

    Relationship between Debye Temperature and Speed of Sound in Metals

    Homework Statement I'm struggling to understand the relationship between the Debye temperature and the speed of sound in a substance. An example problem given is: Estimate the Debye Temperature of Silicon and Lead, given that their respective speeds of sound are 9150 m/s and 1320 m/s. (not...
  4. Hemmer

    Finding angles in a four sided room

    This is a little problem that I encountered while trying to measure the floor plan of an irregularly shaped reverberation chamber. I have measured the length of the four walls (all of different lengths). However I didn't measure the angles at the corners (which are in general not 90°), thinking...
  5. Hemmer

    Capacitance of Concentric Shells (different charges)

    Homework Statement A thin conducting shell of radius a has charge q. Concentric to this is another shell of radius b (b > a) with a different charge Q. How is the charge distributed and what is the capacitance of the two shells. No hint to the relative polarity of the charges is given...
  6. Hemmer

    Quick Differentiation Qu.

    Homework Statement I have nearly finished a problem. I am at the stage where I have: B(s)\propto\frac{1}{s^{3}} v=\frac{ds}{dt} I want to find the rate of change of B(s), but expressed in terms of a velocity, rather than a displacement. Homework Equations So for displacement: B'(s)...
  7. Hemmer

    Det(A^n) = det(A)^n

    Question. Prove det(A^n) = det(A) ^ n I have: det(AB) = det(A)det(B) (holds for any number of factors) set A=B det(AA) = det(A)det(A) det(A^2) = det(A)^2 ? Is this enough for a proof?