Two soap bubbles of different radii r_(1)andr_(2) are in contact. Determine the radius of the interface.

Two soap bubbles of different radii r_(1)andr_(2) are in contact. Dete

1.	Two soap bubbles of different radii r_(1)andr_(2) are in contact. Determine the radius of the interface.
Answer» Solution :If `p_(1)andp_(2)` be the excess PRESSURE in soap bubbles of radii `r_(1)andr_(2)` respectively, then the RESULTANT excess pressure is given by, `p=p_(1)-p_(2)` If R be the radius of the interface, then `(4sigma)/r=(4sigma)/r_(1)-(4sigma)/r_(2)` (or) `1/r=1/r_(1)-1/r_(2)` (or) `1/r=(r_(2)-r_(1))/(r_(1)r_(2))` (or) `r=(r_(1)r_(2))/(r_(2)-r_(1))`