Recent content by astenroo

Thank you for the help :biggrin:

Then to "conserve" charge it should be the W- boson :)

Homework Statement Hi all! I was wondering in two Feynman diagrams (1 and 2) 1) in an electron positron annihilation two photons are created. Now, is the virtual electron the exchanged particle? I'm having problems understanding the diagrams. 2) A proton decays to a neutron as a...

Heh, so true. Thank you :)

Heh, I actually suck at calculus, so when I end up with a fairly straight forward solution, I get the feeling I've done something wrong :) Calculus cannot be simple :D So, my first attempt was F(x)=-mvk/x^2, and if v(x)=k/x then F(x)=-mk^2/x^3. Thanks for the hints.

Homework Statement A particle of mass m moves along a frictionless, horizontal plane with a speed given by v(x)=k/x, where x is its distance from the origin and k is a positive constant. Find the force F(x) to which the particle is subject. Homework Equations F(x)=m\ddot{x}...

Thank you very much for your help. Goes for you as well cupid.

Ok, and then I suddenly began thinking: Let's say that plates 1, 3, 5 and 7 are + and 2, 4 and 6 are -. Do I have a field between plates 1&2 and 2&3 etc? I believe I have a field, but I am not completely sure.

Well, if they are in parallell, then the total capacitance will be the sum of each "sub-capacitor".

Yes I understand how the area affects capacitance. But, in a variable capacitor, can each pair of "+- plates" be considered as a separate capacitor? If so, then they are in parallell, aren't they?

Homework Statement Hi again! I've been handed an assignment in which we are to find the capacitance of a variable capacitor consisting of seven semicircular plates with a radius of 2 cm spaced 1 mm from each other. Every other plate is connected to a common +terminal, and every other to a...

Thank you for your replies. I actually managed to solve the integral, but haven't been able to log on to the forum earlier. I did the u substitution and it worked fine fine. Thank you all again for your help!

Homework Statement I need help with an integral, since my calculus skills aren't the greatest. I need help with getting from this \pik\sigmay\int \frac{2x dx}{(x^{2} + y ^{2})^{3/2}} (i) to this \pik\sigmay\frac{-2}{(x^{2} + y ^{2})^{1/2}} (ii) I integrate from 0 to a (didn't...

Aaargh... What is the major malfuntion with LaTex? The period should be 2 pi sqrt (m/k)...

m\frac{d^{2}r}{dt^{2}} + Gm\frac{4\pi \rho}{3}r = 0 should then be the required equation. Ok, so far so good. Then the period is, don't know if I need to derive it from the diff, T = 2 \pi \sqrt{\frac{m}{k}} . From where it then is just to insert values and I should be done with periodic...