Recent content by Kelly Lin

I mean that I also cannot catch what the question wants. haha! But my other questions are about internal energy! That's really weird, though…

The result will be x=Nl-(N-r)l=rl Oh! Then the configuration will be \frac{N!}{r!(N-r)!}=\frac{N!}{(\frac{x}{l})!(N-\frac{x}{l})!} But, x can also be (N-r)l so the configuration above have to be multiplied by 2. However, in this point of view, we view each section independently as an arrow. In...

For the entropy in the system, since S=-k<lnP_{r}>=-k\sum_{r}{P_{r}lnP_{r}} we get S\approx -k\int{P(x)lnP(x)}dx=...=(-\frac{k}{2})(1-ln(\frac{2}{\pi N}))\approx -\frac{k}{2} \\ A=-\int S dT = \frac{1}{2}kT \\ U=A+TS=\frac{1}{2}kT-\frac{1}{2}kT=0 *A=free enegy; U=internal energy So weird...

I think this is more viable!

Thank you very much for your diagrams! I got it! The relative velocity of the bead is a(\dot{\theta}+\omega)! Thanks again!

How about " the velocity of the bead relative to a non-rotating reference frame moving with the center of the circular hoop". The center of the circular hoop also rotates, so how can I find a non-rotating reference that is moving as the center of the circular hoop? Sorry! I still don't get it! I...

Is it because the direction of the tangential velocity is always changing? Thus, my equations will only be satisfied when the tangential velocities from both of them are parallel.

Homework Statement Homework EquationsThe Attempt at a Solution I know we can solve it by letting x=acos(\omega t)+acos(\theta+\omega t)\\ y=asin(\omega t)+asin(\theta +\omega t) and put their derivatives into the Lagrangian. But, I want to check the other points of view whether it is wrong...

So you mean if N=2 there are 3 configurations?

Also, why can't N=2 chain be folded? Thanks!

But the question mentions that each segment can be orientated in positive or negative directions. Don't we consider the direction (arrow) in different cases?

Is it what the question means?

But, I think the first question asks the total number of specific x. Or, can the polymer be folded? This really make the answers of two questions different.

Actually, I have another question. How come the second question asks about the total number of configurations? In my opinion, there are infinite configurations depend on unlimited x. Does the question ask about the average configuration number? Thanks!

Thanks! Reading mistake!