Recent content by elessar_telkontar

What's the transformation law for the permutation (or Levi-Civita) symbols?

I have a mnemotecnic rule for remember the signs of the 3 basical trigonometric functions, however this is in spanish, and I can't get a english version. The rule reads: CUST where C is cosine S sine and T tangent, and U is a connector that has no mathematical sense (If we don't put U the...

I never said LH has failed. In fact if you see what i have wrote I say that the only thing is that LH is not inteded for this limits. And dextercioby, I think that is not elegant. In mathematics and physics I have learned that a elegant thing is some thing that is symmetric and has a simple...

Please try to help me!

I think the L'Hospital Rule is not failing, simply for certain problems is not necessary since problems of this kind are resolvable by algebraic methods since they are pseudoindeterminate forms. Something like this is, too, when a limit that implies a functions like sines, cosines or...

Well, you may to remember that the matrix of a homomorphism or linear application, or transformation between to vectorial spaces is defined by the results of applying trasformation to basis vectors of any basis of the origin space (in this case a basis of \mathbb{R}^{3}). This is not...

I'm trying to demonstrate the following proposition: Let \vec{\alpha}(s) be a natural parametrization of an arc C. Then: \vec{\alpha}(s+h)=\vec{\alpha}(s)+\left(h-\frac{\kappa^2h^3}{6}\right)\hat{t}+\frac{1}{2}\left(\kappa...

I'm taking a course on astrophysics, and at this time I get the astrophysics of stars. In this section, I have to use the Planck radiation formula, but I have got it for the frecuency of radiation. What's the one for wavelength? I have found one but I tried to reconstruct the one for frecuencies...

thank you so much.

I am gathering my mechanics notes and I put into it some examples. When I get the Hamilton principle I put a section for some basic variation calculus. There's the problem of brachistochrone, I try to solve it, but I get stuck with a integral: the integral that I should make minimal is (I'm...

thanks for the help

yes...partially. because that ecuation states that angular momentum is parallel to angular velocity, and I know it's only valid when the rigid body is rotating around a principal axis. Then, what's the most general eq?

L=Iw with w the angular velocity

the angular momentum L is L=rxmr. for a discrete system is only the summation to all particles. but I have used then the equation of movement for rotation, that says the variation with time of angular momentum is equal to the torque. d/dt(sum(rxmv))=sum(rxF), d(L)/dt=T If I take a...

well. I have another question: Is there a relation between the angular momentum about an axis passing through CM and other angular momenta passing through other points of the rigid body, like the Parallel axes theorem for moments of inertia?