Re: Conservation of angular momentum

On Jun 2, 6:24 pm, "Greg Neill" <gneill...@xxxxxxxxxxxxxxx> wrote:
"Timo A. Nieminen" <t...@xxxxxxxxxxxxxxxxx> wrote in messagenews:Pine.WNT.4.64.0706030639000.1252@xxxxxxxxxxxx

You have, of course, done something like dropping the puck onto the rod
with the rod supported at both ends and seen how high the puck bounces
back?

Has he also measured the friction between the puck and
the rails? If the amount of kinetic energy left in the
puck after collision is small, it may be simply lost via
friction. Does the puck bounce or twist a bit during the
collision?

He also hasn't specified the precise dimensions of all the
levers he's supposedly tried. He says there's anomalous
behavior after some mass of lever, but hasn't said
precisely how the dimensions are varied to vary the mass.
He also hasn't provided an estimate of the pivot friction
for each lever (say by timing the damping rate for free
rotation).

The more this drags on, the more I get the impression that
he's making it up as he goes along.

I am not making up anything. My tests are not difficult to replicate
at all. In all the tests, I used square rods one foot long. With the
(acrylic) rods of mass m or 2m there is no problem, both angular
momentum and kinetic energy are conserved. The problem starts when the
mass of the rod is 4 m or greater (m is the mass of the cylinder). The
steel rod of mass 6m I used is made of steel (the machine shop at the
U had it). I already said the dimensions are 1/4 x 1/4 x 12 inches,
and its mass is 100 grams. If the problem is solved as a thought
experiment, there is no friction, the lever is rigid, there is no
sound or any energy loss everything is ideal. How come both angular
momentum and kinetic energy are not conserved? Clearly, some
theoretical assumption is wrong.

Peter

.

Relevant Pages

  • Re: Ive got your hanging mass right here
    ... > "A sphere of mass M is supported by a string that passes over a light ... > horizontal rod of length L. Given that the angle is theta and that the ... Friction helps you here. ...
    (sci.physics)
  • Re: Conservation of angular momentum
    ... with the rod supported at both ends and seen how high the puck bounces ... Has he also measured the friction between the puck and ... precisely how the dimensions are varied to vary the mass. ... for each lever (say by timing the damping rate for free ...
    (sci.physics)
  • Re: What is the " ACTUAL " length ?
    ... rods in the calorimeter and the center of mass of the collision (and ... particle distribution) have relative motion. ... of a system was when he generated his theory of relativity. ... you compare the length of a rod against markings of a ruler in two ...
    (sci.physics.relativity)
  • Re: What is the " ACTUAL " length ?
    ... rods in the calorimeter and the center of mass of the collision (and ... particle distribution) have relative motion. ... of a system was when he generated his theory of relativity. ... you compare the length of a rod against markings of a ruler in two ...
    (sci.physics.relativity)
  • Re: Was Einstein the most ignorant, immoral, stupid, dishonest plagerist,
    ... in frame 'A' as seen from frame 'B' ... in motion gets when c->infinite zero length and infinite mass, ... inertial mass -> infinity. ...
    (sci.physics.relativity)