1. ### Practice Questions (Lagrangians + Hamiltonians)

Looks good. Thanks.
2. ### Practice Questions (Lagrangians + Hamiltonians)

I need to brush up on L and H. Does anyone know of any sources of practice for these two? Any problem sets? Thanks.
3. ### Quantum physics self study

You can jump into Zettili straight away but I do not recommend it.
4. ### Quantum physics self study

Since you've only done Physics 1 & 2, you should work on strengthening your Classical Mechanics before jumping into Quantum. Perhaps, before getting Zettili for QM (here: http://tinyurl.com/zettiliqm [Broken] you could use Taylor's Classical Mechanics text (sophomore-junior level), found here...
5. ### Physics Forums 4.0 is coming!

Nice one, Greg. Can't wait for 4.0! Now, back to lurking...
6. ### Does the action have any physical significance?

So the action is just a mathematical tool; I guess that's why I didn't expect it to have any physical meaning (like the Lagrangian).
7. ### Does the action have any physical significance?

After studying the methods of Lagrange and Hamilton for a bit I still find myself uneasy about the action. I don't even know how to define it other than the integral of the Lagrangian with respect to time: $$I=\int_{t_1}^{t_2}\mathrm{d}t\, L(q,\dot{q},t)$$ Does the action have any...
8. ### Classical An Introduction to Mechanics by Daniel Kleppner and Robert J. Kolenkow

Calculus 1 is all you need for K&K. Lagrangian and Hamiltonian mechanics are (unfortunately) not covered in K&K. A similar book in classical mechanics (which you should get after K&K or use it alongside it), Taylor, Classical Mechanics does include Lagrangian and Hamiltonian mechanics along with...
9. ### Course of theoretical physics

You should be able to handle them; it seems you already have the necessary prereqs.
10. ### Self-studying physics

Once you finish (at least) the mechanics segment of Young and Freedman, you should go for this book: Kleppner and Kolenkow - An Introduction to Mechanics. edit: Make sure you have a good grasp on calculus I material before getting this book, as it is used when solving problems and explaining...
11. ### Electric field above a circular loop

Yes, that was the angle I meant. That makes sense. I guess I'll have to be careful about my notation; I should have also included the step where the line integral transforms into an integral for ##d\theta##. Thanks for the help!
12. ### Electric field above a circular loop

The radial component of the electric field cancels out at every point due to the symmetry of the circle and the fact that the electric field arises from a line charge. This leaves us with the z component of the electric field, which can be calculated by carrying out the following integral (is it...
13. ### Electric field above a circular loop

Homework Statement Find the electric field a distance z above the center of a circular loop of radius r that carries a uniform line charge λ. Homework Equations $$E=E_r\hat{r}+E_z\hat{z}$$ $$E_r=\frac{\lambda}{4\pi\epsilon_0}\int_0^r\frac{1}{\mathcal{R}^2}\sin{\theta}\,dr$$...
14. ### A question about conservation of momentum (Lagrangian)

Apparently it seems like a convention. Correct me if I'm wrong but Landau shows that ##L=L'## under Galilean transformations. Did you want me to explain how? Unless that's the case, then I guess him going to the action is probably a convention, a way to prove this invariance. I think if you...
15. ### A question about conservation of momentum (Lagrangian)

I think its just another way of proving Galilean invariance (I'm not very familiar with the Galilean invariance of the Lagrangian). Do you mind showing me how they go about proving this (the part where they go to the action)? I might be able to use that information and relate it to the value of...