Problem P. 4667. (October 2014)

P. 4667. At each vertex of a regular tetrahedron there is a point-like charge, they all have the same magnitude and they are alike charges. What should the magnitude of that opposite point-like charge be, which is placed at the centre of the tetrahedron, in order that the net electrostatic force exerted on each charge is zero? What is the interaction energy of the system?

(5 pont)

Deadline expired on November 10, 2014.

Statistics:

80 students sent a solution.
5 points:	Asztalos Bogdán, Balogh Menyhért, Bartók Imre, Bekes Nándor, Berta Dénes, Blum Balázs, Csathó Botond, Csorba Benjámin, Englert Franciska, Fehér Balázs, Fekete Panna, Forrai Botond, Fülöp Erik, Jakus Balázs István, Kaposvári Péter, Kasza Bence, Kormányos Hanna Rebeka, Kovács Péter Tamás, Körtefái Dóra, Molnár 157 Marcell, Németh 017 András, Orosz Bálint, Öreg Botond, Sal Kristóf, Szabó 789 Barnabás, Szász Norbert Csaba, Szentivánszki Soma , Tihanyi Áron, Tomcsányi Gergely, Tompa Tamás Lajos, Trócsányi Péter, Varju Ákos, Wiandt Péter.
4 points:	19 students.
3 points:	12 students.
2 points:	9 students.
1 point:	5 students.
0 point:	2 students.

Problems in Physics of KöMaL, October 2014