A charge Q  is distributed in a spherical volume of radius $R(=2.2\text{ m})$ , such that the volume charge density is $\rho =(\alpha /r)$  where $\alpha$   is a constant and  r is the distance of point from the centre of the sphere. Two point charges $-Q$   each are released from rest from points equidistant from centre inside the sphere as shown in the figure Assume point charges can easily move inside the dielectric charged sphere without any obstacle. Relative permittivity of the medium in which charge is distributed (bounded) is unity. 
[Given $\frac{1}{4\pi {\epsilon }_0}=9\times {10}^9\text{ S.I. unit,}$ $Q=4.84\times {10}^{-9}\text{C},\sqrt{2}=1.4,$    In solving use  $\sqrt{2}=1.4$  when  $\sqrt{2}$  is in numerator. If in denominator then rationalise it then use $\sqrt{2}=1.4$   in numerator.]