Recent content by ximath

I am studying DC circuits and trying to derive formula for power; that is in fact P = I.Vab where Vab is the potential difference between two terminals of a circuit element. From my previous studies, I know that. P = dW / dt I assume that for a small interval, dt, a single...

You're right, I had seen it, but I am trying to figure the things out one by one :) Thanks a lot all, for your help and clarifications, I guess I understand it now. One last thing, just curiosity, if I selected V = 0 at r = a; what would be the corresponding equation for V ? I guess I would...

I am studying electrostatics and totally unfamiliar with the first equation. As far as I understood, the potential difference is integral of E dot dl. In order to find the potential at a point, I thought we need to take this integral. Hmm, I guess I start to understand a little bit of it...

It makes sense, supposing we know the potential difference. But if this isn't the case, in order to calculate it, don't we still need to integrate ?

But again, don't we still need to get our hands dirty with angles and stuff that are related to vectors ? I mean, in order to find the potential we need to integrate the dot product (E dot dl) which means we still need to deal with the angles... Is it really simpler than finding the components...

Hi, thanks a lot. I am in fact aware of the analogy between gravitation and electrostatics. However, although it helps clarifying a little bit, I am still not able to understand the reason why we have such concepts. How does it help us?

Hi all, I have a simple question related to electrostatics. We have the concept of electric field which is a vector field and makes sense. I am aware that it is just a virtual concept in fact, defined as force per unit charge, in other words, it doesn't exist. However, I understand the reason...

Hi Doc Al, thanks a lot! As far as I know I am free to choose any closed surface in fact, however, symmetrical ones are preferable since they help us calculate the electric field. If I used a cube instead of a cylinder, would it also have the symmetry property ? In other words, on the surface...

Hi All, I am studying Gauss' law and have learned that using symmetry, we need to select a cyclinder in order to calculate electric field of an infinite plane sheet of charge. 2EA = \frac {\sigma A} {\epsilon} That equation is written using Gauss' law and hence E field is found...

Hi, I am a little bit confused about singular solutions and their relationship with IVP's and decided to ask you. As far as I understood, the IVP's could be in a form: y' = f(x,y) y(x0) = y0 To obtain a general solution, we could use separable eq. method. I have learned that...

Dear All, I have learned the Uniqueness and Existence theorem in last lecture, however, the instructor told us that the proof is omitted because it is beyond scope of the course. I am more concerned with the derivation of the Uniqueness theorem now. I need some clarification here...

Thanks!

Thanks a lot! Now, I would like to prove that w = \sqrt{\frac{g}{L}} I have tried: Ftan = - mg \sin\theta (for simple pendulum) and a = g \sin\theta V = \int g\sin\theta dt 0 to t and X = \int V dt 0 to T/2. Moreover; X = \theta L Then; using w = \frac {2PI} {T} I...

Hmm, so as far as I understand, angular freq. is constant and angular speed (of pendulum) is variable. saying w = sqrt(g/L) ; w is here angular freq. I guess. Can we say that angular frequency is actually angular velocity of a UCM(not the pendulum) analog of our SHM in this case ?

I guess I need to be more precise. Assume we have a simple pendulum. We say that w = sqrt(g/L). Moreover, we say T = 2PI / w It is quite a lot confusing for me to say period is equal to 2PI / w for a simple pendulum. First of all, if the angular displacement was 2PI and w was constant; then it...