The liquid drop half immersed in the liquid is shown below.
The force acting on the drop due to surface tension is calculated as F=Tl =10g(πD) The observed weight of the drop is calculated as, w=wd−wL =ρVg−
ρ
2
V
2
g =
3
4
ρVg Condition for the equilibrium of ball is, F=w Substitute values, 10gπD=