A wire PQ of length 5 cm which is free to move a and fro is attached to a rectangular dipped in a soap solution and raised. Find the force PQ in equilibrium. ( Surface tension of soap =4xx10^(-2)Nm^(-1))

A wire PQ of length 5 cm which is free to move a and fro is attached t

1.	A wire PQ of length 5 cm which is free to move a and fro is attached to a rectangular dipped in a soap solution and raised. Find the force PQ in equilibrium. ( Surface tension of soap =4xx10^(-2)Nm^(-1))
Answer» Solution :Length of the wire `L=5xm =5XX10^(-2)m` Surface tenson `S=4XX10^(-2)Nm^(-1)` When the wire PQ is pulled towards BC, due to surface tension (S) the force required to KEEP PQin equilibrium is `F=Sxx2L` `=(4xx10^(-2))xx(5xx10^(-2))xx2=40xx10^(-4)=4xx10^(-3)N`