Question

A mercury drop of radius `R` is sprayed into `n` droplets of equal size. Calculate the energy expended if surface tension of mercury is `T`.

Answer 1

Correct Answer - `4piT(Nr_(1)^(2)-R^(2))`
`/_U=N(4pir_(1)^(2))T-4R^(2)T` ………..i
`+4piT(Nr_(1)^(2)-R^(2))`
By mass conservation.
`N(2/3pir_(1)^(3)rho)=4/3piR^(3)rhog`
`r_(1)=R/((N)^(1/3)`…..ii
Substitute `r_(1)` from eqn ii in eqn i