A solid shere of radius R carries a charge Q distributed uniformly over its valume. A very small point like piece of it of mass m gets detached from the bottom of the sphere and falls down vertically under gravity. This piece carries charge q. If it acquires a speed v when it has fallen through a vertical height y (seefigure), then :(assume the remaining protion to be spherical).

Options

A. `v^2 = y [(qQ)/(4piin_0R^2ym) + g]`
B. `v^2 = y [(qQ)/(4piin_0R(R + y) m)+g]`
C. `v^2 = 2y [ (qQR)/(4piin_0(R + y)^3m) + g]`
D. `v^2= 2y[(qQ)/(4piin_9R (R +y) m) + g]`