Molecules on the surface of the liquid have 

If $T$ is the surface tension of a soap solution, the amount of work done in doubling the radius of a soap bubble of radius $r$ is 

Two soap bubbles have radii in the ratio of $4 : 3$. What is the ratio of work done to blow these bubbles? 

$1000$ droplets of water having $2 \mathrm{mm}$ diameter each coalesce to form a single drop. Given the surface tension of water is $0.072{\mathrm{Nm}}^{-1}$. The energy loss in the process is 

Amount of energy required to blow a bubble of radius $5 \mathrm{cm}$ (surface tension of soap is $30\times {10}^{-2} \mathrm{N} {\mathrm{m}}^{-1}$) is 

Work done in blowing a soap bubble of diameter $2 \mathrm{cm},$ is $\left(\mathrm{S}.\mathrm{T}.=3\times {10}^{-2}\mathrm{N} {\mathrm{m}}^{-1}\right)$

The surface tension of soap solution is $0.035 \mathrm{N} {\mathrm{m}}^{-1}.$ The energy needed to increase the radius of the bubble from $4\mathrm{cm}$ to $6\mathrm{cm}$ is 

A wooden stick $2\mathrm{m}$ long is floating on the surface of water. The surface tension of water $0.07 \mathrm{N} {\mathrm{m}}^{-1}.$ By putting soap solution on one side of the stick, the surface tension is reduced to $0.06 \mathrm{N} {\mathrm{m}}^{-1}$. The net force on the stick will be 

A rectangular film of liquid is extended from $(4 \mathrm{cm}\times 2 \mathrm{cm})$ to $(5 \mathrm{cm}\times 4 \mathrm{cm}).$ If the work done is $3\times {10}^{-4} \mathrm{J},$ the value of the surface tension of the liquid is