----- Original Message ----- From: Robin van Spaandonk <[EMAIL PROTECTED]> Date: Tuesday, January 8, 2008 4:38 pm Subject: Re: [Vo]:Another SMOT Test
> In reply to Terry Blanton's message of Tue, 8 Jan 2008 07:39:31 - > 0500:Hi, > [snip] > >I don't follow you. The presence of the magnets changes the momentum > >of the ball regardless of the initial PE as long as it does not > >change. > [snip] > That's just the problem. The initial PE does change, because it > doesn't only > comprise the gravitational PE due to the height of the track, but > also the > magnetic PE between the magnets and the ball itself. IOW the ball > can "feel" the > magnets even at the starting position. That may mean that you have > to do a > little more work with your hand to place the ball on the track > when the magnets > are present than when they are not, > or you may need to push the > all a fraction > harder to get it to start rolling down the track. The latter can > easily be > eliminated by making the track slope down at the start, and using > a barrier to > hold the ball in place. Removing the barrier would not add energy > to the ball. > However that still doesn't solve the first problem. The only way I > can see > around that is to make the whole track a closed loop. The initial magnetic force on the ball could be made neglible by lengthing the track between the magnets and the release point. Harry > The problem is thus that the work you do with your hand doesn't > get measured. > BTW still on the topic of magnet motors, the video that was posted > recentlymatches the description I saw in a magazine (I think) > years ago of a magnetic > generator that was supposed to have been used by the US Army in > Vietnam. It also > comprised two magnetic discs making contact at the rim, but the > axes were not > quite parallel, and the discs were about the same size. > > Regards, > > Robin van Spaandonk > > The shrub is a plant. > Harry
