Dave, I am saying if you carefully measured her final speed while considering losses due to friction and drag, her final speed would be slightly greater than could be explained by conservation of angular momentum alone. This is because she does some work in order to bring her arms inwards. In effect she has converted some internal chemical energy into angular momentum. Or is this wrong?
Harry On Sun, Feb 9, 2014 at 1:33 PM, David Roberson <dlrober...@aol.com> wrote: > Harry, the skater pulls her arms inwards but that does not contribute to > her rotating motion directly. The increased speed is due to the reduction > of her moment of inertia and the conservation law requires for her to spin > faster so that the product of her moment of inertia and angular velocity is > constant. > > Dave > > > > -----Original Message----- > From: H Veeder <hveeder...@gmail.com> > To: vortex-l <vortex-l@eskimo.com> > Sent: Sun, Feb 9, 2014 1:05 pm > Subject: Re: [Vo]:Linear and Angular Momentum > > > A spinning figure skater is often used to demonstrate the principle of > conservation of angular: > > https://www.youtube.com/watch?v=jeB4aAVQMug > > However, the skater also exerts some muscular energy to pull her arms > inward, so doesn't this boost the angular momentum slightly? > > Harry > > > > >
