Physics - Fluid Question with Solution | TestHub

In this case, work done = increase in surface energy, i.e. $\mathrm{W}=\mathrm{T}\Delta \mathrm{A}$ Key point: In calculation, area of sphere have been multiplied with 2, since there are two surfaces in soap bubble. $\begin{array}{rl}& \therefore \mathrm{W}=\mathrm{T}\times \left[2\left(4\pi {\mathrm{d}}^2\right)\right]\\ & \Rightarrow \mathrm{W}=8\pi {\mathrm{d}}^2\mathrm{T}\end{array}$