Question 143: Properties of Matter

Question

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

Accepted Answer

$$T.2\pi r + {2 \over 3}\pi {r^3}\rho g = {4 \over 3}\pi {r^3}dg$$
$$ \Rightarrow $$ T = $${{{r^2}} \over 3}\left( {2d - \rho } \right)g$$
$$ \Rightarrow $$ r = $$\sqrt {{{3T} \over {\left( {2d - \rho } \right)g}}} $$

Answer

$$r = \sqrt {{T \over {\left( {d - \rho } \right)g}}} $$

Answer

$$r = \sqrt {{{2T} \over {3\left( {d + \rho } \right)g}}} $$

Answer

$$r = \sqrt {{T \over {\left( {d + \rho } \right)g}}} $$

Answer

$$r = \sqrt {{{3T} \over {\left( {2d - \rho } \right)g}}} $$

Properties of Matter

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

Choose the correct answer: