In the circuit shown, all capacitors are identical. Initially, the switch is open and the capacitor marked (*) is the only one charged. After the switch is closed and the equilibrium is reestablished, the charge on the capacitor marked (*) is Q. What was the initial charge Q 0 on that capacitor?

We received a large number of solutions, not all of them correct, for our December Challenge, Bar Bouncer. We are pleased to recognize the following authors of correct solutions:

Antonio Jorge Aranda Gomez (student, Escuela Superior Polilecnica, Seville, Spain)

Sharmila Balamurugan (student, Women's Christian College, Chennai, India)

Hratch Barsoumian (Haigazian University, Beirut, Lebanon)

Mark Brown (Cretin-Derham Hall U.S., St. Paul, MN)

Phil Cahill (Lockheed Martin Corporation, North Yorkshire, United Kingdom)

Daniel Carlin (Naval Academy Preparatory School, Middletown, RI)

David A. Cornell (emeritus, Principia College, Elsah, IL)

Don Laston (Lacombe, Alberla, Canada)

Oscar Lscucha García (student,...

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