Question

Two liquid drops of same radius are falling through air with a terminal velocity ‘v’. If the drops coalesce to form a single drop, the terminal velocity will be

• A. 2v
• B. v
• C.
• D.

Answer 1

The correct option is C

$R=n^{\frac{1}{3}}.\gamma v‘\propto R^2\therefore v‘\propto (2^{\frac{1}{3r}}{)}^2$

$\therefore v‘=2^{\frac{2}{3}}{r}^2\Rightarrow v‘=4^{\frac{1}{3}}$