Recent content by Muizz

  1. M

    QM: Writing time evolution as sum over energy eigenstates

    Suppose I have a 1-D harmonic oscilator with angular velocity ##\omega## and eigenstates ##|j>## and let the state at ##t=0## be given by ##|\Psi(0)>##. We write ##\Psi(t) = \hat{U}(t)\Psi(0)##. Write ##\hat{U}(t)## as sum over energy eigenstates. I've previously shown that ##\hat{H} = \sum_j...
  2. M

    Numerically find the energy of the delta-well's bound state

    Right. That makes a lot of sense (and explains why they're telling my to vary ##V_0/t##.. Changing this little thing gets a much nicer curve, I'll still need to verify if it's the correct curve, but I call this progress :) Thanks! Edit: Turns out I'm ~2 orders of magnitude off now.. Progress...
  3. M

    Numerically find the energy of the delta-well's bound state

    I'm working on an assignment where I'm required to numerically find the energy of a delta-potential's bound state. To do this, we've converted the time-independent schrödinger equation to an eigenvalue problem with E the eigen value, ψ the eigen vector and H a matrix as follows: with ##t =...
  4. M

    Finding the effect of air resistance on period of oscilation

    I agree. The derivation gets a little hairy though, and already got 5 pages of those, so I decided to keep it out for now. I can always add it, but that's a lot of work which is time I'll have to pay for somewhere else. Usually I derive everything I use, even little things such as the inertial...
  5. M

    Finding the effect of air resistance on period of oscilation

    Yeah, I found that too. But I like this because it shows a different angle of the situation, which is what I was attempting to do. Doing mechanics without differential equations is like doing special relativity without lorentz transformations, it's just not happening. But that doesn't mean you...
  6. M

    Finding the effect of air resistance on period of oscilation

    https://en.wikipedia.org/wiki/Logarithmic_decrement It's mainly based on that article and a message I got from someone: Another resource:
  7. M

    Finding the effect of air resistance on period of oscilation

    I have no objection against the calculus. I'm just trying to explore the science: to find out if there are other avenues that would still work. That includes a different way of measuring the torsion constant if such a way exists (provided that you don't directly measure it but use the...
  8. M

    Finding the effect of air resistance on period of oscilation

    Yeah, I agree. The source you've given is still using differential equations of motion though. Is that really something you're fundamentally stuck to? Edit: No, I'm unable to measure the period in a vacuum chamber, the anti-vibration desks just wouldn't be able to be moved.
  9. M

    Finding the effect of air resistance on period of oscilation

    "Where air resistance does become relevant is in finding the value for $\kappa$ (torsion spring coefficient)." ^^ Well, mainly because I just want to explore the science behind it. I can solve the differential equation, or I can try to find a different way which should also work ^^ I'm only...
  10. M

    Finding the effect of air resistance on period of oscilation

    Homework Statement I'm currently working on the "cavendish" experiment and wish to use/develop a method separate from the casus we've been provided. Now I've nicely calculated and derived everything I need to know, including all the corrections that have to be made for the mass of the rod, the...
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