What mass should be suspended from the wire $CD$ to keep it in equilibrium?

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

If the surface area of the soap solution is increased,then its surface tension

$A$ metal wire of length $L$ and density $d$ floats horizontally on the free surface of water. What is the maximum radius of the wire such that it does not sink in water? [$T$ = surface tension of water, $g$ = gravitational acceleration]

How does the surface tension of a liquid change with temperature?

The surface tension of a liquid is $70 \, dyne/cm$. In $MKS$ system its value is