Recent content by 582153236

  1. 5

    Buckingham Pi Theorem: Choosing Common Variables

    Homework Statement In buckingham pi theorem, you have p=n-k dimensionless groups (π1, π2,...) where n=number of total variables and k=number of total units among the variables For example, let's say we want to relate: ρ~m/L3 (density) μ~m/L*t (viscosity) v~L/t (velocity) d~L (distance) Da~L2/t...
  2. 5

    Dimensional Analysis of Flux Equation for cross filtration

    Homework Statement The following equation is presented in my textbook, with very little context and J is simply described as the "trans-membrane fluid flux, which can be modeled by using Darcy’s law." Typically in this bioseparations class, when we discuss permeate flux, it is a unit volume...
  3. 5

    Error Propagation for Tube Volume

    Homework Statement You have a cylindrical tube for which you know the length is 16±0.1 cm and the radius is 8±0.1 cm, what is the error of the volume? Homework Equations The Attempt at a Solution V = π*82*16 = 3216.99 cm But since the r term is squared, must we account for its error twice...
  4. 5

    Finite difference method with derivative boundary conditions in MATLAB

    Homework Statement I'm trying to plot the steady state concentration of yA vs. x, yB vs x and yu vs x using centered finite difference method. Homework Equations The Attempt at a Solution τ represents the dimensionless time variable, so steady state would mean that the left hand side of...
  5. 5

    Is the System with Nonlinear ODEs at Steady State (0,0) Stable?

    Thanks! If instead I had dx1/dt=-x13+x2, would it be valid to keep z1 as it is defined now (z1=x1-0) and would dz1/dt=-z13+x2 be true? Since the first term of the series expansion of x3 is x3
  6. 5

    Is the System with Nonlinear ODEs at Steady State (0,0) Stable?

    Homework Statement Find whether this system is stable or unstable at the steady state (x1,x2)=(0,0) dx1/dt = -x1+2sin(x1)+x2 dx2/dt=2sin(x2) Homework Equations The Attempt at a Solution z1=x1-0 z2=x2-0 dz1/dt=-z1+z2+2z1 dz2/dt=2z2 Jacobian = [ 1 1 ] [ 0 2 ] so the system is unstable. This...
  7. 5

    Implicit Euler's Method Application

    Homework Statement dx/dt= -x2-2x(1+t+t2) x(1)=2 estimate x(1.2) with h=0.2 Homework Equations Implicit Euler: I was taught that we must solve for yk+1 using Newton's method: This doesn't seem like it will work because Newton's method assumes a function of only one variable. According to...
  8. 5

    How Does Including the Quadratic Term Affect the Newton Iteration Formula?

    Homework Statement The Newton iteration formula is based on a Taylor series expansion of the function f(x) around an estimate of the root xn, truncated after the linear term. You are asked to derive a more accurate iteration scheme as follows: Start from the Taylor series expansion of f(x)...
  9. 5

    Potential and Kinetic energy commutator

    Homework Statement [T,V]=[TV-VT]ψ Homework Equations T=(-ħ2/2μ)∂2/∂x2 V=(1/2)kx2[/B]The Attempt at a Solution [(-ħ2/2μ)∂2/∂x2((1/2)kx2ψ)]-[(1/2)kx2(-ħ2/2μ)∂2/∂x2(ψ)] I think my problem is with executing the chain rule on the first term: (-ħ2/2μ)[x2ψ''+2xψ'+2xψ'+2ψ-x2ψ''][/B] The x2ψ''...
  10. 5

    Normalizing wave functions / superposition

    A remote control shot a single photon at a window that has a 50% chance of transmitting and 50% chance of reflecting photons. Once the photon wavepacket hits the glass (without an observer present), it propagates as a superposition of states, one in which it was transmitted and one in which it...
  11. 5

    Can Zero Be a Valid Eigenvalue for an Eigenstate?

    If an operator (O) acts on a function ψ and transforms the function in a scalar manner as described below, it is said to be in an eigenstate: Oψ=kψ in this case, O is the operator and k some scalar value. My question is essentially if k=0, can this still be a valid eigenstate? for example, O...
  12. 5

    Why are objects different colors—reflection, absorption, or transmission?

    What is the origin of light the color in the following objects and does the color of these objects involves absorption, reflection, and/or transmission of light: a beam of blue light a white sheet of paper a red shirt a black shoe a transparent yellow solution My guesses in order: not...