The radii of two soap bubbles are r1 and r2. In isothermal conditions, two meet together in vacuum. Then the radius of the resultant bubble is given by

The radii of two bubbles are r1​ and r2 . In isothermal condition, two meet together in a vacuum. then  Under isothermal condition.P1V1+P2V2=PVP1= 4Tr1, P2=4Tr2, P=4TR& volume of bubble =43πR3 Hence 4Tr1×(43πr13) +4Tr2×43πr23=4TR×43πR3 R2= r12+r22