Question

A 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 sticks the surface tension is reduced to 0.06 N/m. Net force on the stick is

• A. 0.01 N
• B. 0.02 N
• C. 0.03 N
• D. 0.04 N

Answer 1

The correct option is A 0.01 N

Net force on stick $F_1-F_2=(T_1-T_2)l$
Given $T_1=0.07,T_2=0.06$
Net force, $f=(0.07-0.06)l$
$=0.01\times 2=0.02N$