A small charged ball is in state of equilibrium at a height h above a large horizontal uniformly charged dielectric plate having surface charge density of sigma C//m^2. (a) Find the acceleration of the ball if a disc of radius r (ltlt h) is removed from the plate directly underneath the ball. (b) Find the terminal speed (V_0) acquired by the falling ball. Assume that mass of the ball is m, its radius is x and coefficient of viscosity of air is eta. Neglect buoyancy and assume that the ball acquires terminal speed within a short distance of its fall.

A small charged ball is in state of equilibrium at a height h above a

1.	A small charged ball is in state of equilibrium at a height h above a large horizontal uniformly charged dielectric plate having surface charge density of sigma C//m^2. (a) Find the acceleration of the ball if a disc of radius r (ltlt h) is removed from the plate directly underneath the ball. (b) Find the terminal speed (V_0) acquired by the falling ball. Assume that mass of the ball is m, its radius is x and coefficient of viscosity of air is eta. Neglect buoyancy and assume that the ball acquires terminal speed within a short distance of its fall.
Answer» Answer :(a). `(GR^(2))/(2h^(2))` (B). `V_(0)=(MGR^(2))/(12 pi ETA xh^(2))`

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