Physics - Fluid Question with Solution | TestHub

Under isothermal conditions the surface tension remains constant. If $r$ is the radius of the digger drop, then Final surface energy $=$ Initial surface energy $\therefore 8\pi r^{2}T=8\pi r_1^{2}T+8\pi r_2^{2}T$ $\therefore r^2=r_1^2+r_2^2$ $\therefore r={\left(r_1^2+r_2^2\right)}^{\frac{1}{2}}$