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In the image that I've attached with this thread you can see proof of surface energy+surface tension. This scaned image is from my school book. When I was going through this topic I wound that in this
increase in surface area = 2lx
which according to me isn't reasonable. I discussed about it mwith my teacher but I'm not satisfied with his answer.
According to me
increase in surface area should be = lx.
Please post your comments on this912_22502_scan0003.jpg

Rajat Goel , 15 Years ago
Grade 11
anser 1 Answers
Fawz Naim

In this question there are two surfaces of the soap film. The increase in the area of the soap film=lx+lx=2lx.

 lx is the increase in the area of one surface.The other surface has also a length equal to l and width equal to x

Therefore net increase in the surface area of the soap film=2lx

Last Activity: 15 Years ago
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