Elementary Kinematics 2: Explanation of the WaxingRadiance LensMagSpinner
Pulled by the center, dragged by an off-center, or vice-versa: the effect is the same. Pulled onto the contact surface by gravity, or by a lower magnet: the effect is the same.
Magnetism per se has nothing to do with the spinning; it is produced by a simple force couple as taught in elementary engineering dynamics.
Of course… if you didn’t get that far before graduating, it is unlikely that you have worked hundreds of problems concerning the topic, like real engineers had to do when _they_ were struggling through a full college career.
So now might be a good time to review your Beer and Johnston.
You do still have your copy don’t you? Well, it is available on the internet now, even in dumbed down versions for people who may have graduated too early to learn anything valuable.
