A drop of liquid of mass 1.8 × 10^-5 kg falls away from the bottom of a charged conducting sphere of radius 20 cm, carrying with it a charge of 1 nC…

A drop of liquid of mass $\displaystyle 1.8 \times 10^{-5} \mathrm{~kg}$ falls away from the bottom of a charged conducting sphere of radius $\displaystyle 20$ cm , carrying with it a charge of $\displaystyle 1$ nC and leaving on the sphere a uniformly distributed charge of $\displaystyle 2.5 \mu \mathrm{C}$. The speed of the drop, after it has fallen $\displaystyle 30$ cm is $\displaystyle \sqrt{\frac{\mathrm{x}^3}{2} \mathrm{~m} / \mathrm{s}}$. The value of x will be \_\_\_\_. $\displaystyle \left(\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2\right)$