1000 spherical drop of water each 10^-8m in diameter coalesce to form one large spherical drop the amount of energy liberated in this process in joules is (surface tension of the water is 0.075M/m)

Options

A. `10.75 pixx 10^-15`
B. `6.75 pixx 10^-15`
C. `8.65 pixx 10^-15`
D. `3.88 pixx 10^-15`

Answer

B

Explanation

Energy librated,
`W=4piR^(2)[n^(1/3)-1]xxsigma`
`R=1/2 xx 10^(-8)=0.5xx10^(-8)m`
`therefore W=4pi[0.5xx10^(-8)]^(2)[(10^(3))^(1/3)-1]xxsigma`
`=4pixx2.5xx10^(17)xx(10-1)xx0.075`