Two spherical soap bubbles of radii `r_1` and `r_2` in vacuume coalesce under isothermal condition. The resulting bubble has radius `R` such that

Options

A. `R = ((r_(1) + r_(2))/(2))`
B. `R = [ (r_(1) r_(2))/((r_(1) + r_(2)))]`
C. `R = sqrt((r_(1)^(2) + r_(2)^(2)))`
D. `R = r_(1) + r_(2)`

Answer

C