# Suspend a magnet on a pendulum above a repelling magnet

• Happyholland
In summary, the conversation discusses the possibility of creating perpetual motion with a chaotic magnetic pendulum. The person believes that the pendulum would eventually stop due to gravity and the repelling force of the magnet. However, they acknowledge that their limited knowledge in physics may be causing them to overlook something obvious. They hope someone can provide an answer to their question before they attempt to build a perpetual motion machine themselves.
Happyholland
Hi, I was pondering a question after seeing a video about chaotic magnetic pendulums.

If you were to suspend a magnet on a pendulum above a repelling magnet, would it stop moving or would you get perpetual motion?

My guess is it would stop moving but I can't think of how. Gravity would try to pull the pendulum to the center put the repelling force of the magnet in the center would prevent it from stopping there. I don't see it stopping at a certain angle if the friction on the attachment point of the rod is low, thus creating perpetual motion.

I'm an arborist by profession (no more physics involved than judging which side of the tree is heavier and where its going to land when I cut it down) and I have a feeling I'm overlooking something obvious here because so many attempts at perpetual motion machines have been made and none seem to work.

I hope someone here can (and I certainly think someone can) awnser my question before I go out building myself some silly science experiment to lead myself to an obvious conclusion.

Thanks in advance and sorry for my butchered English.

Happyholland said:
My guess is it would stop moving but I can't think of how. Gravity would try to pull the pendulum to the center put the repelling force of the magnet in the center would prevent it from stopping there. I don't see it stopping at a certain angle if the friction on the attachment point of the rod is low, thus creating perpetual motion.
It will eventually stop at angle. Since there is not a single equilibrium point, the pendulum will be very sensitive to any vibration or air flow, and may appear to keep moving, but that doesn't make it perpetual motion.

## 1. How does the magnet stay suspended above the repelling magnet?

The magnet stays suspended because of the repelling force between the two magnets. This force counteracts the force of gravity, allowing the magnet to stay in place.

## 2. What type of magnet is needed for this experiment?

You will need two strong magnets, one that is repelling and one that is suspended on a pendulum. The strength of the magnets will determine how easily they repel each other.

## 3. Can the pendulum magnet be replaced with any other object?

Yes, as long as the object is magnetic and light enough to be suspended by the repelling magnet. However, the pendulum motion may not be as smooth as it would be with a magnet.

## 4. Is there a specific distance that the magnet needs to be suspended above the repelling magnet?

The distance between the two magnets will depend on the strength of the magnets and the desired pendulum motion. It may require some experimentation to find the optimal distance for your specific setup.

## 5. How can this experiment be used to demonstrate magnetic forces?

This experiment can demonstrate the concept of magnetic repulsion, where two magnets with the same polarity will push each other away. It can also show how this force can be strong enough to counteract the force of gravity and keep the magnet suspended in the air.

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