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. `10.75pixx10^(-15)`
B. `6.75pixx10^(-15)`
C. `8.65pixx10^(-15)`
D. `3.88pixx10^(-15)`

Explanation

Volume of small spherical drops = `(4)/(3)pir^(3)`
Volume of larger spherical drops = `(4)/(3)piR^(3)`
n small spherical doprs combine to form large drops.
`therefore " " n((4)/(3)pir^(3))=(4)/(3)piR^(3)`
`rArr " " R=n^(1//2)r`
`"Here" " " n=1000,r=(1)/(2)xx10^(-8)m`
Amount of energy liberated
=Change in area `xx` surface tension
`=4piR^(2)(n^(1//2)-1)xx0.075`
`=6.75xx10^(-15)j`