$W = mg = \frac{4}{3}\pi {r^3}\rho g$

$T = \frac{4}{3}\pi {r^3}\sigma g$

$and\,F = 6\pi \eta vr$

When the body attains terminal velocity net force acting on the body is zero $i.e.,$

$W - T - F = 0$

And terminal velocity $v = \frac{2}{9}\frac{{{r^2}\left( {\rho  - \sigma } \right)}}{\eta }g$

As in case of upward motion upward force is twice its effective weight, therefore, it will move with same speed $10cm/s$