Question

Calculate the work done in blowing a soap bubble of diameter 0.6 cm against the surface tension force. (Surface tension of soap solution = 2.5 x ${10}^{-2}N{m}^{-1}$)

Answer 1

$r_1=0$

$r_2=0.006$m

$S=2.5\times {10}^{-2}$$N{m}^{-2}$

work done $=S\times 8\pi \times (r^2-r^1)$

$=2.5\times {10}^{-2}\times 8\pi \times (.006{)}^2-0^2)$

work done $=0.226$ joule