The minimum possible velocity at lowest point can be $\sqrt{7.2} \mathrm{\,m} / \mathrm{s} .$ The corresponding velocity at the highest point will also be minimum
${\frac{1}{2} m v_{f}^{2}-\frac{1}{2} m v_{i}^{2}=-m g(2 r)+q E_{0}(2 r)} $
${v_{s}=6 \,m / s}$

Statement $1$ : It is not possible to make a sphere of capacity $1$ farad using a conducting material.
Statement $2$ : It is possible for earth as its radius is $6.4\times10^6\, m$