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

The correct option is 0.02 N.

Underlying Concept:
Surface tension is defined as the force per unit length acting perpendicular to an imaginary line drawn on the liquid surface. When a wooden stick floats on water, the liquid surface on both sides of the stick exerts a pulling force on it due to surface tension. These forces act in opposite directions, perpendicular to the length of the stick.

Initially, pure water is on both sides of the stick, so the forces are equal and opposite, resulting in a net force of zero. When soap solution is added to one side, it reduces the surface tension on that side, creating an imbalance in forces.

Given Data:
Length of the wooden stick:
$L=2\mathrm{m}$
Surface tension of water on one side:
$T_1=0.07\mathrm{N}/\mathrm{m}$
Reduced surface tension due to soap solution on the other side:
$T_2=0.06\mathrm{N}/\mathrm{m}$

Step-by-Step Calculation:
The force exerted by surface tension on one side of the stick is:
$F_1=T_1\times L$
The force exerted by surface tension on the other side of the stick (in the opposite direction) is:
$F_2=T_2\times L$

The net force on the stick is the difference between these two opposing forces:
$F_{\mathrm{net}}=F_1-F_2$
Substitute the expressions for forces:
$F_{\mathrm{net}}=(T_1-T_2)\times L$

Substituting the given values:
$F_{\mathrm{net}}=(0.07-0.06)\times 2$
$F_{\mathrm{net}}=0.01\times 2$
$F_{\mathrm{net}}=0.02\mathrm{N}$

Therefore, the net force acting on the stick is 0.02 N towards the side with the higher surface tension (pure water).