A soap film in on a rectangular wire of size 4 cm xx 4 cm. If the size of the film is changed to 5 cm xx 5 cm, then calculate the work done in this process. The surface tension of soap film is `6xx10^(-2) Nm^(-1)`

Answer

`1.08 xx 10^(-4) J`

Explanation

Increase in area of soap film is `Delta A = 2xx[5xx5 - 4 xx4] = 18 cm^2 = 18 xx 10^(-4) m^2`
work done ` = S.T. xx Delta A = (6 xx 10^(-2) xx 18 xx 10^(-4))`
`= 1.08 xx 10^(-4) J`