P. 4440. A hemispherical insulating shell is charged positively, and is fixed. The charge distribution on the shell is uniform. At a point on the symmetry axis, which is exactly at a distance of the radius measured from the centre of the hemisphere O, a small negatively charged bead is released. The speed of the bead is v0 when it reaches the centre O.
What will the speed of the bead be when it reaches the shell? (Neglect the effect of gravity.)
Deadline expired on 10 May 2012.