$\rho = \frac{{{\rho _{{\rm{liq}}}}}}{2}$
When body (sphere) is fully immersed then,
Upthrust = wt. of sphere + wt. of water poured in sphere
==> $V \times {\rho _{{\rm{liq}}}} \times g = V \times \rho \times g + V' \times {\rho _{{\rm{liq}}}} \times g$
==> $V \times {\rho _{{\rm{liq}}}} = \frac{{V \times {\rho _{{\rm{liq}}}}}}{2} + V' \times {\rho _{{\rm{liq}}}}$==> $V' = \frac{V}{2}$


$(i)$ Gravitational force with time
$(ii)$ Viscous force with time
$(iii)$ Net force acting on the ball with time
|Take atmospheric pressure $=1.0 \times 10^5 \mathrm{~N} / \mathrm{m}^2$, density of water $=1000 \mathrm{~kg} / \mathrm{m}^3$ and $g=10 \mathrm{~m} / \mathrm{s}^2$. Neglect any effect of surface tension.]
