Building a self looping "SMOT"

[norman6538]

Which post, Norman, gives details of your setup. Your work looks interesting and I would like to have a go.

Paul-R

the video is here but I recommend elecar's because it has more potential.

http://www.youtube.com/watch?v=4FzK2XKQ-74

Norman

[LibreEnergia]

...Good luck, it will defy current scientific principles because we have all been taught that pendulums cannot go past the level of the dropped point but this one does. So scratch your head and ask where does the force/work come from to make it go higher than its dropped point? That discussion will probably take 20 years....

I don't believe any scientific principles are being violated by this setup.  We haven't be taught that "pendulums cannot go past the level of the dropped point". What we are taught and is self evident is that a pendulum will not spontaneously move to a point of higher POTENTIAL than the point it was dropped. Now, the normal geometry of this situation where gravity alone is acting dictates that height and potential are directly related.  In this case your observation that  it 'cannot go higher than the dropped point' is correct. 

However, When you introduce magnets into the situation this symmetry is no longer necessarily true. One thing that I can assure you is that the pendulum will never gain potential more that the combined magnetic and gravitational potential it has at the starting point.

All that happens in you video is that you move the pendulum BY HAND to a particular potential energy state and release it. It then swings to another location with EXACTLY THE SAME energy state (minus any losses caused by air resistance or bearing losses.)

Due to the magnetic field not necessarily being uniform that equipotential point will not necessarily be at the same height as it was released.

No energy gain has occurred and nothing of interest from an OU perspective has occurred.

[norman6538]

 LigreEnergia - go to the bench and do something and rest your keyboard.Then come back and tell us what you learned.  That is what I did.



Norman

[LibreEnergia]

LigreEnergia - go to the bench and do something and rest your keyboard.Then come back and tell us what you learned.  That is what I did.

Norman

You may very well have done that, but without a suitable theoretical framework to hang your observations on you came to an erroneous conclusion.

[MileHigh]

I think that it's a challenge to understand and talk in terms of magnetic potential energy for some people.  Gravitational potential energy is more intuitive.

Imagine a very simple setup, a straight track with two aluminum rails.  A few inches away from the track there is a magnet.

             M

A===========B

So you release the ball at point A, it's attracted to the magnet and speeds up and then stops at point B.

This is the type of effect that you are playing with when you put magnets around your closed-loop tracks and place the metal ball at a certain starting point.

It may seem that you got energy from the magnet and the ball moved from point A to point B for "free."

However, the truth of the matter is that in a way nothing happened.  The ball moved down the track but no energy was gained and likewise no energy was lost.  When you release the ball and it starts moving, the energy in the system does not change at all.  We are ignoring friction.

Can any of you track builders explain that?  You need to be able to explain that and fully understand it to work more effectively with your setups.  You should become comfortable in discussing magnetic potential energy and use that terminology in your discussions.