A film of ethanol at 20°C has a surface tension of 22.3 mN/m and is maintained on a wire frame as . Consider the film with two surfaces as a control mass and find the work done when the wire is moved 10 mm to make the film 20 × 40 mm.
Assume a free surface on both sides of the frame, i.e., there are two surfaces 20 × 30 mm
