Recent content by Kruger

Ah, ok, then I understand it now. I think the first thing I were trying to do was integrating an object, namely the current density J, which is simply everywhere zero except at the boundaries of the cylinder over an area which intersects the current density vector J perpendicular. This cannot...

Ah, so you mean I have to integrate the surface current density K (unit A/m) over the line my curve intersects the cylinder? So I get K*length(curve) = K*L.

Well, I think we can assume the cylinder to be a perfect conductor carrying only a surface charge density at its outside. So inside there will not be any current.

Homework Statement The problem is to find the magnetic field within a rotating cylinder (infinitely long) that has on its surface a given surface charge density p. I made a picture of the problem to illustrate this. The only hint given: "the magnetic field outside the cylinder is zero...

Homework Statement Given the function g(x)=e^u(x) where u(x) = -(1-x^2)^(-1). I have to integrate this from -1 to 1. The Attempt at a Solution I know the function is symmetric. It is enough to integrate it from 0 to 1 to get the real value of the integral. Well, beside that I have...

I'm so confused because sometimes Steiner's theorem isn't used and sometimes it is used for rolling objects. Can you please generalize, when I have to use Steiner's theorem for rolling objects? Would be really helpful.

Homework Statement Consider a spere with momenta of inertia of 2/5*m*r^2 that rolls down a plane surface (no friction). I want to calculate the rotational energy of the sphere when it has speed v0. Homework Equations Erot=1/2*I*w^2 The Attempt at a Solution My only problem is: Do...

Ok, this seems sensible. I try to calculate G. ...

Sorry, I cannot use this Latex editor. But you're right, I have to write out the inner product (in reference ot the basis I wrote down) in the matrix version.

Homework Statement Given the Vectorspace V of the real polynoms and the sub space L(1, t, t^2). On V there's a inner product defined as follows: <u(t), w(t)> = integral(u(t)*w(t), dt, -3, 3) I have to find the inner product of the subspace in reference of the basis (1, t, t^2)...

Ok, this way I can solve it easy. It is no problem. I want to try it the other way. I mean, I know the solution of the problem in the frame of the moving particle p0 and want to transform it into the lab system (my system).

Well, the diffraction angle of p1 relative to p0, the energy E0 and momentum p0 are given as well as the masses m0,m1,m2.

Homework Statement A particle with momentum p0, mass m0 and energy E0 decays into two particles with mass m1 and m2. Find the energy of the particle E1 and E2. Homework Equations Four-momentum! The Attempt at a Solution I calculated the energy of particle 1 in S' (system where...

Mhhh, isn't there anyone that can help me?

Homework Statement Let F(AB) be the Frobenius-Norm in respect of the matrix A*B. And let ||A||2 be the operator norm. I have to show that F(AB)<=F(B)*||A||2 2. The attempt at a solution I wrote F(AB) in terms of sums and then tried to go on. But I don't know how I could include the...