Re: Work - impulse

"Peter" <Poakfield@xxxxxxx> wrote in message
news:1146498373.400025.20430@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
That is exactly the case. To be specific: we have two systems, each
consisting of a puck and a lever, and the only difference is that the
lever of one of them has a little more, or less, mass than that of the
other; if we exert the same force, through the same distance on each
puck, and each puck collides with its respective lever and stops on
impact, I say the levers acquire different kinetic energies.
This is vague but as I recall you were confused about
translational and rotational KE earlier in this thread.

No, I am not confused. Suppose each system is in a spaceship: when each
puck is accelerated, the spaceship recoils briefly, but when the puck
hits the lever and stops, the spaceship returns to its original
position and linear momentum. This was made clear by PD's problem,
which I solved. After the collision, in both systems, the levers have
angular momentum, but because angular momentum is also conserved, the
spaceships, as a whole, rotate in the opposite direction, so their
total angular momentum is zero, as it was before the collision.

Perhaps you mean as it was before the puck was accelerated?
In accelerating the puck to give it linear and angular
momentum w.r.t. the lever, the spaceship will recoil both
linearly and angularly (if that's a word). The sums of
the momenta for the whole system should be individually zero
at all times.


.

Relevant Pages

  • Re: Work - impulse
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    (sci.physics)
  • Re: Work - impulse
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  • Re: Work - impulse
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  • Re: Collision puck-lever
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  • Re: Work - impulse
    ... lever with backwards linear momentum, ... results from accelerating the puck, ... spaceship, ...
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