Recent content by leonmate

I was reading about WiMAX networks and how they can provide a 30mbit connection to a user 50km away! Now, I don't have a great understanding of data transfer but I assume inverse power law applies?? Pf = Pi / 4*pi*r^2 At 50km Pf = Pi / 10^10 * pi For Pf = 30mbit/sec = 30*10^6 Pi must equal...

OK, so I've made a little progressFirst thing we have to do is find the finite-difference approximation for the u'' matrix for a staggered grid So, Newton-Raphson method, discretise using finite-difference approximations of the derivatives u'' = (ui+1 + ui-1 - 2ui) / dx2 So, the first thing...

Hey guys, I'm going to be honest and say I'm so stuck on this assignment - I really need help! I've took on a third year computational physics course last year - turn your weaknesses into strengths someone told me. Well, I failed and I'm back doing it again this year! So, I just have to pass...

Ok, how do I get y = cos(wt) I got it once, now everytime I do it I end up with a sin in there. y'' + w2y = 0 y(t) = ert y''(t) = r2ert ay'' + by' + cy = 0 r2 + w2 = 0 r = ±2π i (w = 2π) y(t) = c1 cos (2πt) + c2 sin (2πt) y'(t) = -2πt c1 sin (2πt) + 2πt c2 cos (2πt) Plug in my y(0) = 1 and...

My lecturer gave me this, the first two slides are relevant

Hey guys, I've worked through some more, here's what I have y1(t) = (cos(wt) + i sin(wt)) y2(t) = (cos(wt) - i sin(wt)) y(t) = A y1(t) + B y2(t) y(t) = A(cos(wt) + i sin(wt)) + B(cos(wt) - i sin(wt)) y'(t) = Aw(-sin(wt) + i cos(wt)) + Bw(-sin(wt) - i cos(wt)) Plug in boundary conditions...

Re-writing, r2 = -ω2, so what should r be? ... what I've got is r2 = -w2 r = i*sqrt(w2) w = 2π - I am given this in the question r = ±2π i http://tutorial.math.lamar.edu/Classes/DE/ComplexRoots.aspx I'm mostly following Ex 4

I did do a course with ODEs, but I wound up taking some time off and my memory of them isn't great. I probably need to go over it much more as this course progresses. So, I had a read through that site - very helpful thank you. This is what I've come up with... y'' = w2y = 0 y(t) = ert...

Homework Statement I've attached an image of the problem question, it's Q1 I'm working on This is what I have so far: we have two components of SHM, position x and velocity v. when x = 0, v = a maximum, when v = 0, x = a maximum this is represented by sin & cos functions. where x =...

When we have two commuting operators we can have two values inside the ket, both are eigenstates of my operators? Ok, I see that I can, I'm stuck on the how. Also, I'm confused at how eigenvalues seem to be plucked out of thin air in every example I look at. I can find how to find eigenvalues...

I've been working through some dirac notation and I'm stuck... Here's where I'm at: I understand that an expectation value: <x> = ∫ ψ* x ψ dx = <ψ|xψ> = <ψ|x|ψ> Also, we can say H|ψ> = E|ψ> where E is an eigenvalue of the operator H and |ψ> represents a state your acting on. I get that you can...

Ok, found a handy website with an article that's explained this well: http://www.physicspages.com/2011/07/20/angular-momentum-eigenvalues/ I was curious about this statement: 'We can assume that the eigenvalue of for is for some number . That is, for this eigenfunction' (above eq 19) Why...

Ok, fair enough, I'm finding this a really tough subject Perhaps my lecture notes aren't great, ill try one of those textbooks thanks

Hoping this is in the right section! The module is nuclear and atomic physics but it crosses over into quantum occasionally. I've attached an image of the bit I'm trying to work out. I've got an exam on this topic in just over a week, so sorry if these posts get annoying, I have a feeling I'm...

Simple question really, I'm not sure why the constant pulled out of the derivative becomes negative (-w2). I've tried looking for answers by googling but can't come up with anything. I feel like its because the first term (1,1) is negative but I want to be sure. Thanks