Recent content by amind

Aren't you missing something ? In the reference frame of the package, it has two perpendicular components of acceleration, one arising because our frame is non-inertial, i.e. the centrifugal force AND the acceleration arising from the angular acceleration of the merry go round. And thus the...

Gotcha, the trick is writing r as n - (n-r) in the first step and then using the property C(n, r) = C (n, n-r)

I got (n+1)*an+1-an-(n+1) How do I convert an+1 to an ?

Homework Statement If $$a_n = \sum_{r=0}^{n} \frac{1}{\binom{n}{r}}$$ Find $$\sum_{r=0}^{n} \frac{r}{\binom{n}{r}}$$ in terms of an and n 2. The attempt at a solution Let $$f(x) =\sum_{r=0}^{n} \frac{x^r}{\binom{n}{r}}$$ Then, an = f(1). Observe that f'(1) is the required sum. I was thinking...

Thanks! You made it really clear!

Oh yeah, I messed that up while posting. "...Thus, I reason that the charge on the outer surface of the charged sheet in this case would be 0, and on the inner surfaces of both would be and respectively and charge on the outer surface of the uncharged sheet would be +q". i.e. 0 +q...

Problem: Consider two parallel and large sheets with a surface area . One has a charge and the other is uncharged. q | | | | | | | | | | What would be the electric fields on the three regions as divided by the sheets ? General solution to problems like as told...

Sorry for not replying , I am not a frequent visitor for physicsforums and I didn't looked after your approach worked for me. Yes , I think you are right , I rechecked the formula , I wrote the original formula wrong , I got the right answer now. :s:s That was the first result I got for a...

Thank you very much . I've been stuck with this problem for a while. > [SIZE=16px]I believe the problem is your very first equation. The derivation of that assumes the object is external to the lens ... I think you mean the derivation of the lens formula not the formula concerning refraction...

Oops, I didn't noticed that , Also about that step , it is right if that factor of ##\mu_2## is included. Corrected steps. ( Is is not possible to edit the first post of a thread in the new forums ? I didn't find an "Edit" button. ) $$ v = \frac{R \mu_2}{3\mu_1-\mu/2} $$ $$ \begin{align} m &=...

Homework Statement A goldfish in a spherical fish bowl of radius R is at the level of the center of the bowl and at distance R/2 from the glass. What magnification of the fish is produced by the water of the bowl for a viewer looking along a line that includes the fish and the center, from the...

I'm sorry for that , I'm not great in calculus and I probably skimmed through the posts. :(

> I have worked it out. It amounts to zero by symmetry. Although , I couldn't solve but it is not zero according to wolfram alpha. see : http://www.wolframalpha.com/input/?i=%E2%88%AB+%28e%5E%28i*q*r%29+cos%282%CE%B8%29%29dq

Reading all that it seems this is still debatable and there is no one common viewpoint , you choose the theory you find the best in your opinion ;)(kind of like quantum mechanics , /sarcasm )

Thanks... Reading the old post.