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?
A. `2 xx 10^(-2)` N/m,
B. `2.5 xx 10^(-2)` N/m
C. `3xx 10^(-2)` N/m
D. `3.5 xx 10^(-2)` N/m
