Problem P. 4113. (November 2008)
P. 4113. A spherical cap of radius r and of width d, is placed onto the top of the sphere of the Van de Graaff generator, the radius of which is R. The spherical cap is made of aluminum foil of density . At what voltage value will the spherical cap ascend from the sphere of the Van de Graaff generator?
Deadline expired on 11 December 2008.