Recent content by jason12345

Ok, how do I do that? It's an amazing book, all the same.

I'm posting this question here because I recall a certain book as being an outstanding introducton to algebraic structures and therefore worth knowing about in 2012. The problem is that I borrowed it from a library in the early 1990s and I can't remember it's name! Here's what I remember...

Can the conservation of the 4-momentum be proved, or is it a postulate of special relativity?

For c=1, but in general {\bf V=P}c^2/E. yes?

@itbell and Meir Achz, yes I see what you mean! The key for me was visualising the disintegration of a particle into p1 and p2, while using conserving 4-momentum. This really is a very elegant, beautiful result, which I can't find anywhere in my copy of Goldstein, 3rd edition, nor in any...

Does anyone know of a standard way of calculating the com frame velocity for two particles moving at arbitary velocities in the lab frame? It's strange that this standard result isn't even in Goldstein's et al book

I think you mean velocity where you state radius. I agree that angular velocity is constant.

Thanks for your reply, although I disagree with it :) I could also argue that the radius of the circular motion is constant and so there isn't an acceleration towards the centre - but there is: v^2/r

The angle is between the string and the axis of symmetry the pendulum rotates around.

For a conical pendulum, there is an instantaneous centripetal acceleration. Does this mean there is an instantaneous angular acceleration of the pendulum towards the center?

You should read this paper: Thomas precession: correct and incorrect solutions Grigorii B Malykin1 A wealth of different expressions for the frequency of the Thomas precession (TP) can be found in the literature, with the consequence that this issue has been discussed over a long period...

Can anyone criticize this solution of mine? The Lagrangian for a relativistic particle moving in an electromagnetic field is given by L = - \frac {mc^2} \gamma + q~( \vec u(t)\cdot \vec A(\vec x,t) -\Phi(\vec x,t))Conservation of the canonical momentum requires the Lagrangian to be...

Since it's a conserved quantity d/d\tau\ (p_\mu + (e/c)x^\nu F_{\nu\mu}) = 0 d/d\tau\ p_\mu = - (e/c)u^\nu F_{\nu\mu} Which is just the Lorentz force equation. I suspect you can carry out your procedure for time varying fields to give another conserved quantity which also gives rise...

That's given me a lot to think about - thanks! Maybe I could try for something simpler to start with so: How would I find \nabla\Lambda as the other terms with U independent of (x,y,z)? Perhaps I could use some vector identity?

What is the general strategy in solving vector equations involving grad and the scalar product? In particular, I want to express \Lambda in terms from \mathbf U \cdot \nabla\Lambda = \Phi but it looks impossible, unless there is some vector identity I can use. Thanks in advance.