A small spherical droplet of density \(d\) is floating exactly half immersed in a liquid of density \(\rho\) and surface tension \(\mathrm{T}\). The radius of the droplet is (take note that the surface tension applies an upward force on the droplet) 

\(\mathrm{B}=\left(\frac{2}{3} \pi \mathrm{R}^{3}\right) \rho \mathrm{g}\)

\(\mathrm{F}=\mathrm{T}(2 \pi \mathrm{R})\)

\(\mathrm{m}=\mathrm{d}\left(\frac{4}{3} \pi \mathrm{R}^{3}\right)\)

\(\left(\frac{2}{3} \pi \mathrm{R}^{3}\right) \rho \mathrm{g}+\mathrm{T}(2 \pi \mathrm{R})=\mathrm{d}\left(\frac{4}{3} \pi \mathrm{R}^{3}\right) \mathrm{g}\)

\(\mathrm{T}(2 \pi \mathrm{R})=\left(\frac{2}{3} \pi \mathrm{R}^{3}\right) \mathrm{g}[2 \mathrm{d}-\rho]\)

\(\mathrm{R}=\sqrt{\frac{3 \mathrm{T}}{(2 \mathrm{d}-\rho) \mathrm{g}}}\)