Recent content by DougD720

A picture's worth a thousand words... here's the scenario if there were only two sets of times, hence the potential function only changes once:

Hi guys, I'm trying to solve the S.E. For a potential that's time dependent but the time variable is not continuous. Essentially the potential is a finite square well and it shifts over time but not continuously. I.e. At time 0<t<t' it's a finite square well centered about some x' At...

Hi All, I'm working on a little side-project (not school related) in Java for analyzing Financial Stocks (I understand the stuff I'm doing can be done online but I'm trying to learn some graphing/plotting in Java). Anyways, my question has to do with calculated EMAs (Exponential Moving...

Homework Statement A heavy nuclei can be approximately considered as a spherical ball with uniform volume density  = 4/3 * 10^ 25 C/m3. If a nuclei with total charge Q = 92e splits into 2 equal spherical piece and they fly away. What will be the total electric energy change during this...

Thank you, that was very helpful and explained very well. Here's the issue I'm butting up against in the problem. I have the identity written down in my notes but I don't get it. I'm getting the left hand side down to (same as above): ∇(A_{i}B_{j}δ_{ij}) (Keeping the deltas in because I...

Just got an email from the Prof. Apparently the HW problem I'm stuck on was written wrong (Dot products in the 2nd and 4th terms instead of Cross products). Hopefully I'll be able to figure it out now. If not I'll let you know. Thanks

Hey guys, this is for my classical E&M class but it's more of a math problem. Homework Statement Show: ∇(\vec{A} . \vec{B}) = \vec{B} \times (∇ \times \vec{A}) + (\vec{B} \times ∇)\vec{A} + \vec{A} \times (∇ \times \vec{B}) + (\vec{A} \times ∇)\vec{B} Homework Equations I tried...

Ah... Think I've got it now, I wasn't adding in the KE of the Mass on the End, 1/2 M V^2, I was under the (incorrect) impression it was bundled in with the (1/6)mV^2... knew it was a dumb mistake on my part. Thanks!

Homework Statement This is a 3 part problem, mass M on a spring of length l with mass m. The first part was to derive the Kinetic Energy of one segment dy, second part was to Integrate this and get the Kinetic Energy of (1/6)m(V^2) where V is the velocity of the Mass M at the end of the...

Thank you! I just didn't know if I could use the gamma from the time-dilation part, but yeah, duh, that makes perfect sense. Thanks!

Homework Statement The radius of our galaxy is 3x10^20m (30000 lightyears). (part a): Can a person in principle travel from the center to the edge of the galaxy in a normal lifetime? Explain using Time-Dilation, then Length-Contraction. Homework Equations d\tau = dt \sqrt{1...

I don't have a QM text but I know of separation of variables from diff. eq. I have to take the time to read through your explanation but from skimming it it looks like I can follow your steps. Thank you!

I'm in need of some direction... I have differential equation experience and partial integrals/derivatives but I believe this is a partial differential equation now that both the x and y variables have been introduced and I have not worked on partial diff eqs. Where do I start to tackle this...

Thank you, I'll work that one out

Hey Everyone, So I've been working on some very basic QM mathematics. Basically I've worked out the wave equation for a particle in one dimension (briefly) like so: -\frac{\hbar 2}{2m}\psi"(x) + V(x)\psi(x) = E\psi(x) V = 0 for 0 < x < L ; (L = "Length" of the Boundary) =>...