Can a spring beat the charges?

Physics Teacher

Volumn 42, Issue 8, 2004, Pages 472-476

  Partensky, Michael ^a   Partensky, Peretz D ^b,c  

^a BRANDEIS UNIVERSITY   (United States)

^b UNIVERSITY OF CAMBRIDGE   (United Kingdom)

^c UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 85007574002     PISSN: 0031921X     EISSN: 19434928     Source Type: Journal    
DOI: 10.1119/1.1814321     Document Type: Article

References (5)

1. Michael B. Partensky "The elastic capacitor and its unusual properties," ArXiv: physics/0208048 (2002). This is a slightly more complex example of a similar anomaly, which still only requires high school physics. See http://arxiv.org/abs/physics/0208048
2. 0 (for distance), while the general behavior is universal.
3. min = -4/27 C -0.148 C.
4. 2Prime; is only locally stable (or "metastable," see e.g. http://encyclopedia.thefreedictionary.com/Metastable). The charge q returns toward this point as long as disturbances are not too large. The equilibrium is not globally stable because once q has crossed the unstable equilibrium (the peak of curve 2 in Fig. 4) there is no restoring force to return it back. When the corresponding barrier is sufficiently large, however, it is possible to ignore this caveat and effectively treat the equilibrium as stable (c.f. relevant discussion on the effect of finite size at the end of Discussion section).
5. D.C. Giancoli, Physics: Principles with Applications, 5th ed. (Prentice Hall, Upper Saddle River, NJ, 1997).