Dual CPU nodes?

Ken Chase math at velocet.ca
Tue Oct 22 12:43:14 PDT 2002


On Tue, Oct 22, 2002 at 01:30:44AM -0700, Karen Shaeffer's all...
> On Tue, Oct 22, 2002 at 02:15:08AM -0400, Ken Chase wrote:
> > 
> > [A friend told me about blowing a circuit once at his lab and he had a large
> >  metal bracelet on. When the circuit blew, he was standing under the power
> >  run (about 5 feet over his head in the ceiling) and his bracelet shot up his
> >  arm and yanked on his wrist, quite hard! He had a bruise to prove it.  It
> >  was only a 20A circuit - what would cause that? Dangerous wiring situation?]
> 
> 
> That would be Faraday's Law. Look it up in any College Physics Book. The
> bracelet was a closed circuit that was enclosing Magnetic flux from the
> power line. Basically, the rate of change of the magnetic flux enclosed
> within the cross-sectional area bounded by the closed circuit resulted
> in a force on the bracelet. Since the cirucit breaker broke, this
> resulted in a large rate of change and a proportional force.

why have I never seen this before? Why was it of such force as the
bruise the wrist while standing 5 feet away? (from what I recall of
my university e&m physics (not much :) magnetic fields are extremely
week at such distances usually. Im also referring to how can wiring
of a 20 amp circuit cause such a strong force. (Im estimating a force
of more than 50N based on the description - it yanked his whole arm
in the air and bruised him.)

/kc

> 
> cheers,
> Karen
> -- 
>  Karen Shaeffer
>  Neuralscape; Santa Cruz, Ca. 95060
>  shaeffer at neuralscape.com  http://www.neuralscape.com
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-- 
Ken Chase, math at velocet.ca  *  Velocet Communications Inc.  *  Toronto, CANADA 



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