Magnetic Rotation: Will South Pole Move to North?

AI Thread Summary
The discussion centers on whether a magnetic setup in a frictionless environment will cause the south pole to rotate towards the north pole, leading to overall system rotation. It is suggested that internal forces, such as the attraction between the poles, cannot generate a net torque to initiate movement. The concept of controlling the direction of rotation, similar to a compass, is also questioned. Additionally, the setup's configuration with equal mass bars is examined, but the conclusion is that it does not lead to rotation. The thread ultimately emphasizes that internal forces cannot create perpetual motion, leading to its closure.
pbhuter
Messages
28
Reaction score
0
If I have a magnetic setup in frictionless, etc. area as follows:

N
/
/
/
---------------------S

Will the "south" pole rotate up to the "north" pole, causing the system as a whole to rotate?
 
Physics news on Phys.org
pbhuter said:
If I have a magnetic setup in frictionless, etc. area as follows:

N
/
/
/
---------------------S

Will the "south" pole rotate up to the "north" pole, causing the system as a whole to rotate?
Why not the other way around?
 
A.T. said:
Why not the other way around?
It is my understanding (and it has been awhile since magnetics in college) that it would rotate toward "north" - like a compass. But for sure I would like to be able to control the direction of rotation...
 
pbhuter said:
like a compass
Are the vertical and horizontal bars free to rotate relative to each other, like the compass needle can rotate relative the Earth? If, yes do they have the same mass ratio as the a compass needle and the Earth?
 
It is all connected. Ultimately, it is a full cross shape that I am trying to rotate about the center.
 
This is operating in a frictionless environment. Each bar is the same mass, and like I said there are four making a complete cross. I am trying to see if the whole thing will start rotating about the center as the "south pole" is attracted to the "north pole".
 
pbhuter said:
This is operating in a frictionless environment. Each bar is the same mass, and like I said there are four making a complete cross. I am trying to see if the whole thing will start rotating about the center as the "south pole" is attracted to the "north pole".

So you've effectively taken two bar magnets and put on on top of the other, offsetting one by 90 degrees?
 
pbhuter said:
causing the system as a whole to rotate?
No. An internal force cannot cause a net torque.

We don't discuss perpetual motion machines here. Thread closed.
 
Back
Top