Recent content by qoqosz

Ok, thanks.

I know that, but I'd like to derive it somehow.

Let's assume that electron is moving around the unit circle. Using Maxwell equations show what is the frequency of radiating EM waves. How to start with it? What's the form of known variables - current density and charge density?

You're right - I made stupid mistake :( Should be: \frac{1}{\mu c} EB

Ok, thanks. I used \frac{1}{\mu \epsilon} EB as an energy density not an energy flux.

Homework Statement We are given monochromatic point source of EM radiation which power is P=100W. The task is to compute E(r) and B(r). We can assume that r is large enough to treat wave as a plane wave. Homework Equations The Attempt at a Solution First of all - what for do we...

I don't get it. Why there's \frac{\partial L}{\partial v^2}? If we expand function in Taylor series (taking \vec{\epsilon} as an independent variable) there should be only derivatives in respect to that var (epsilon). -edit- I think I got it - from mean value theorem we have: \frac{f(x+h) -...

According to Landau textbook: Having two inertial frames K and K' moving with velocities \vec{v} and \vec{v'}=\vec{v} + \vec{\epsilon} where \vec{\epsilon} is an infinitesimal. We have L' = L(v'^2) = L (v^2 + 2 \vec{v} \cdot \vec{\epsilon} + \epsilon^2). Expanding this expression in powers of...

Am I right?

Well the fact from the 1st task is for me intuitive but I don't understand it's formal proof. Because when some components of T_{ij} are 0 (but not all) than the T_{i'j'} can have no 0 components. So why when all components of T_{ij} are 0 then T_{i'j'} are 0 as well? Is it because changing...

Homework Statement Task 1. Show that if components of any tensor of any rank vanish in one particular coordinate system they vanish in all coordinate systems. Task 2. The components of tensor T are equal to the corresponding components of tensor W in one particular coordinate system; that...

Great, thank you!

Homework Statement We have two frames of reference: K (x,y,t) and K' (x',y',t') such that initially x=x'=y=y'=t=t'=0. Now let K' move with a velocity \vec{v} = v [\tfrac{1}{\sqrt{2}},\tfrac{1}{\sqrt{2}}] Write Lorentz transformations in such a case. Homework Equations The Attempt at...

Ok, thank you both! :)

Ok, I was wrong. x_i is x component of mass position. But in b) I think if L is a matrix of rotation there should be I' = L^T I L.