If the pole is that thin then there will be no spiraling, the puck will execute a circular motion, since there will be no torque. I don't know why he(the author, 'David Morin', I really like his writing style) mentioned 'thin'. I was just looking for a hole in my argument because I don't know...
No, the tension won't cause any change in 'radial' momentum because there is no change in tension as the rope wraps up, because nothing is pulling it except for the pole and no external agent is doing work on the pole. Initially when the puck is driven, all the radial forces are balanced, and it...
A puck of mass 'm' on friction-less ice is attached by a horizontal string of
length 'l' to a very thin vertical pole of radius R. The puck is given a kick
and circles around the pole with initial speed V. The string wraps around the
pole, and the puck gets drawn in and eventually hits the pole...
I think you're right.I thought of the same thing at the beginning. But I think the author has done a technical mistake because of which I was having the trouble. Purcell says 'the change 'at' the surface' must be 4(pi)s, if he said 'across' the surface, I would have been convinced by the same...
Oh... I wanted to write C.G.S, but wrote M.K.S instead, thanks for pointing that out. The problem with the superposition thing is that the scenario doesn't consider a particular arrangement of external charges, but rather generalises the proposition to all the possible arrangements; logically...
The problem I have is about a simple remark made in the book 'Berkeley Physics Course Volume 2, Electricity and Magnetism', chap. 3 figure 3.4 b. It says that if we have an infinite sheet of charge but with 'other charges' present elsewhere in the system, the only thing we can predict is that...
Yes! That should be it, the question did say about the 'high amplitude' of the resultant oscillations, so there's a high possibility that the composite system is showing resonance, i.e the driven system may undergo oscillations at the same frequency as that of the driving system. Thanks for the...
I've tried. But there's so much approximation I needed to use to derive the final relation, (using energy consideration), I'm no longer satisfied with or sure about my answer. So better I thought if it be run by experts. I found both systems to be oscillating with the same freq. and K=w/l.
Yes...
A weight W is suspended from a rigid support by a hard spring with stiffness constant 'K'. The spring is allowed to have only vertical motion. A simple pendulum of length 'l' with a bob of mass 'm' (mg<<W) is suspended from the weight W and is set oscillating in a horizontal direction. After...
my intuition tells me that it must change since KE must be conserved, and for it to be so, the angular velocity must change as the moment of inertia changes with the reduction in mass, but I ain't sure, so pls reply...
Suppose I have a ring of mass 'M' rotating about an axis passing through its center with constant angular velocity 'w', now if its mass changes by dm due to some unknown reason during rotation, will the angular velocity change, assuming no external force acts on it during any point of time?
Thank u DaveC426913... It was a big help! I thought posting here was just a way of gaining knowledge, but now I know it's just learning how to post, thanks for that...
Thanks 'Mikelizzi', for your reply which changed my interpretation of the statement... My prev's interp'n was that the body 'C' is accelerating in the same dir'n as is the motion of body 'B' w.r.t A... So for my 1st interpretation, would the movement of C would still look Curvilinear to B, or...