Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] drop a metal cylinder through a solenoid



On 03/21/2012 02:17 PM, Carl Mungan wrote:
What if one instead drops an aluminum cylinder through a solenoid
(having a constant current): Will the cylinder fall (significantly)
slower than with the current off?

Real solenoid or idealized super-high-aspect-ratio solenoid?

In a real solenoid, the field tapers off at each end, to a
nontrivial degree ... so there will be an effect near the
ends ... but not much of an effect elsewhere.

Motion strictly along a magnetic field line doesn't do
anything. Look at the form of the Lorentz force law.

If this has never been tried before experimentally to anyone's
knowledge, I'll try to set it up and see. But first I thought I'd ask
if either anyone has tried it or can make a definite prediction about
the answer?

Every experiment involving magnetohydrodynamics tests this.
Familiar examples include the ionosphere, tokomaks, et cetera.