Question

A big drop is formed by coalescing 1000 small identical drops of water. If \(E _1 \) be the total surface energy of 1000 small drops of water and \(E_2\) be the surface energy of single big drop of water, the \( E_1 : E_2\) is x : 1 where x = ___.

Answer 1

Correct answer is : 10

\(\rho (^4_3 \pi r^3)1000 = ^4 _3 \pi R ^3 \rho\)

R = 10r

\(E_1 = 1000 x 4 \pi r^2 \times S\)

\(E _ 2 =4 \pi (10 r)^2 S\)

\(\frac {E_1}{E_2} = \frac {10}{1} , \,x = 10\)