Mechanical Properties Of Fluid

Consider a soap film on a rectangular frame of wire of area . If the area of the soap film is increased to , the work done in the process will be (The surface tension of the soap film is )

A drop of water of radius is falling in air. If the coefficient of viscosity of air is , the terminal velocity of the drop will be (The density of water and )

A solid sphere falls with a terminal velocity of in air. If it is allowed to fall in vacuum?

Work done in increasing the size of a soap bubble from a radius of to is nearly (surface tension of soap solution ).