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Re: [Phys-L] Lenz's law



Some on this list, maybe all on this list, will say that asking WHY? takes you 
into metaphysics (philosophy) not physics.  I'm not sure that's always the 
case, but maybe so here.  Conservation of energy is a good answer for the 
underlying physical principle--I think.

[Did do a Great Course audio course on metaphysics which was really much more 
entertaining than any physics course I've taken (or given).]    😉

Richard W. Tarara
Professor of Physics, emeritus
Saint Mary’s College
Notre Dame, Indiana

Free Physics Instructional Software
Windows and Mac
sites.saintmarys.edu/~rtarara/software.html

-----Original Message-----
From: Phys-l <phys-l-bounces@mail.phys-l.org> On Behalf Of pschoch via Phys-l
Sent: Thursday, April 25, 2024 1:09 PM
To: phys-l <phys-l@phys-l.org>
Cc: pschoch <pschoch@ptd.net>
Subject: [Phys-L] Lenz's law


So, here's where I get myself into trouble.   I encourage my students to 
understand why things happen, what causes them, and not just memorize the 
formulas.  And now we've gotten to Induction -- Lenz's law. 
  
The textbook shows them that the induced EMF opposes the change causing it, 
thus the negative sign -- experimentally.  Now I've had a student ask me what 
the underlying physical principle is that results in the negative sign.   
Honestly, I don't think I understand this well enough to give an explanation. 
  
Any help would be appreciated, 
Peter Schoch 
  
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