A good non-linear example is intensity in interference and diffraction
phenomena.
Intensity at the central peak for two point sources:
1+1 = 4
and of course the points of destructive interference provide the opposite
case!
I'm glad this came up, I follow an optics before E&M ordering, and we just
started electric fields, it will be good to remind them of intensity being a
"familiar" non-superposition situation.
Joel R.
| -----Original Message-----
| From: Forum for Physics Educators [mailto:PHYS-L@lists.nau.edu] On Behalf
| Of Edmiston, Mike
| Sent: Wednesday, February 25, 2004 10:19 AM
| To: PHYS-L@lists.nau.edu
| Subject: Re: superposition
|
| Ludwik's heater example is good, but I wonder if students will have a
| feel for it. I think they will have even less feel for the magnetic
| field example. I am looking for examples of supression and synergism
| that students will clearly understand. I have used fake math and
| biological examples because they understand these.
|
| Superposition
| 2+2 = 4
| try to lift something with one arm, then with both arms. The two forces
| just add.
|
| Synergism
| 2+2 = 5
| Take a barbiturate and drink alcohol and get more than you bargained
| for.
| Look with either eye alone, then together. Gain depth perception.
|
| Suppression
| 2+2 = 3
| Take tetracycline for an infection at the same time as taking Tums
| (calcium) for an upset stomach. Tetracycline is ineffective because it
| binds to calcium and is not absorbed into the bloodstream from the small
| intestine.
|
| I like the idea of physics examples because I don't want students to
| think that superposition is always the rule in physics. But often, it
| is. Do people know of other examples beyond what Ludwik mentioned?
| Does anyone have physics examples for synergism?
|
|
|
| Michael D. Edmiston, Ph.D.
| Professor of Chemistry and Physics
| Bluffton College
| Bluffton, OH 45817
| (419)-358-3270
| edmiston@bluffton.edu