Recent content by NTesla

[Mentor Note: this post has been heavily edited to remove numerous insults.] You mentioned that my blind assertion is that Energy is not conserved: In my post#24, I have considered both the cases: Energy being conserved and other case of Energy not being conserved. I have never solely said that...

Even if we consider that Energy is not conserved, then in that case also, the value of tension at the bottom of both, the static portion as well as the falling portion of the chain = ##\frac {\lambda v^{2}}{2}##. Why is this force ##\frac {1}{2}## of the force required to stop a straight falling...

When I equate this d(P.E) with negative of d(K.E), I get an expression for velocity in terms of y: ##v^{2} = gy\frac {2L - y}{L - y}##. Now, when I use the Newton's 2nd law on the entire chain(##\frac {dP}{dt} = F_{ext}##), then I get the expression for tension at the ceiling. From that I get...

Yes, that I understand. When I wrote that I meant that the length of the static portion increases by ##\frac {v}{2}## per unit of time. I should have clarified that in that previous post. Yes. When the top has fallen by y, then the change in GPE is given by: ##d(P.E) = - \frac{\lambda...

Angular momentum of purely vertical falling portion of the chain = ##\lambda (\frac {L}{2} - \frac {x}{2})2rv##. since the velocity of the purely vertical portion, ##v##. However, for the semi-circular portion, the expression for angular momentum about the suspension point is somewhat lengthy...

In the limit ##r=0##, the static portion's length increases by ##\frac {v}{2}##, and the moving portion of the chain falls by velocity ##v##. I'm not sure why you wrote that one of the velocity is zero. Which part's velocity are you referring to as zero velocity.

Just before point D in direction of point E, the acceleration is a. Just at point D, the downward acceleration is less than a, and it's overall acceleration is towards the centre of the semi-circle, and below point D, the acceleration of all the elements would be towards the centre of the...

hmm.. that's a valid point. However, in the limit that the distance between the two points O and A, tending to zero, and the assumption that the chain is infinitely flexible, as if it were a cloth ribbon, I suppose the shape of the bend can be assumed to be an infinitely small curve. In that...

I would like to understand which part did you thought was strange ? Only then, can i attempt to figure out the rationale.

IMO, It's catenary as long as both it's end is fastened to the ceiling. It's not catenary from the moment one of it's end is released. But I would like to know your reasoning for the hypothesis being strange.

Only one portion is falling, i.e. portion DE. When I apply conservation of energy, I'll have to take the speed of portion DE. I'm not sure how would that yield velocity of element of chain that is about to come to stop at point B, where point B belongs to the static portion of the chain ?

Actually, the diagram is drawn for the situation at time t > 0, when the freely falling part has fallen a distance y in time t. At time t = 0, the point O and E, both were exactly at the same point i.e. at point O. The separation distance between point O and A tends to zero, and in that case...

In case of a straight chain falling on a surface, the force required to stop an element of length ##\lambda dx## of the chain is = ##\frac{\lambda dxv}{dt}## = ##\lambda v^{2}##. In case of U chain see fig. below, When the purely vertical portion(DE in pic below) falls a distance ##y##, the...

Who says I cannot be bothered to ask the question here. Did you ask ? Even once ? The answer is NO. Not even once. If you didn't understand the question itself, you should have asked question, or atleast let me know that you are not able to understand the question. I would have tried to frame...

As I've mentioned in post#93 and 96, I'm finding it not just difficult to understand the explanation given in post#92 and 95, but near impossible to understand as to how the explanation given in these 2 posts would help me understand the question that I had raised in post#84. And post#97 is in...