# Do neodymium magnets loose energy?

1. Oct 5, 2011

### mailhiot

Generally, most of the research I have done says that neodymium magnets do not loose their energy, even when dropped or around other magnets, and will last 400 years. But what about if the neodymium magnets are constantly in motion and interacting with each other?

Our system has a Sphere neodymium magnet moving along a "magnet track" with Cylinder neodymium magnets, similar to this Youtube video:

We need to know HOW MANY PASSES a sphere magnet can make before the cylinder magnets along the magnet track loose 10% of their energy. Our system has a sphere magnet passing at a speed of about 1.0 m/s, 3 times per second, so lots of magnetic activity. That means 94,608,000 passes a year!

Can the energy loss of energy for the Cylinder neodymium magnets along the magnet track be calculated ?

Sphere magnet:
1 1/2" diameter Grade N42 - Nickel Plated
http://www.kjmagnetics.com/proddetail.asp?prod=SX8

Track magnets:
1/2" dia. x 1/2" thick Grade N42 - Nickel Plated
http://www.kjmagnetics.com/proddetail.asp?prod=D88

The sphere magnet is moving at about 1 m/s.

The cylinder magnets along the magnet track are about 0.25 inches from the surface, so the sphere magnets are always 0.25 inches away from the cylinder magnets.

I do need a complete calculation that I can show to someone with a Ph.d. in physics who would agree with the calculation.

Can anyone help?

Last edited by a moderator: Sep 25, 2014