Surface tension of the liquid is S . Work done in increasing the radius of soap bubble from S . to 3 R at given temperature will be

Step-by-step solution

Given, surface tension of the liquid is S . Work done in blowing a soap bubble, so as to increase its radius from R 1 = R to R 2 = 3 R is given by W = S ⋅ 8 π [ R 2 2 - R 1 2 ] where S = surface tension W = S ⋅ 8 π [ ( 3 R ) 2 - ( R ) 2 ] = S ⋅ 8 π [ 9 R 2 - R 2 ] = S ⋅ 8 π ⋅ 8 R 2 = 64 π R 2 S