A U-shaped wire is dipped in a soap solution, and removed. A thin soap film formed between the wire and a light slider supports a weight of `1.5xx10^(-2)N` (which includes the small weigh of the slider). The length of the slider is 30cm. What is the surface tension of the film?

Explanation

As the soap bubble has two free surfaces. Therefore, surface tension, `T=F/(2l)`
where l is the length of the wire slider.
l=30 cm
`F=1.5 xx 10^(-2) N`
`T=(1.5 xx 10^(-2))/(2 xx 30 xx 10^(-2))`
`=2.5 xx 10^(-2) Nm^(-1)`.