Question

The surface tension of soap solution is $0.03N/m$. The work done in blowing to form a soap bubble of surface area $40c{m}^2$, in Joules, is:

• A. $1.2\times {10}^{-4}$
• B. $2.4\times {10}^{-4}$
• C. $12\times {10}^{-4}$
• D. $24\times {10}^{-4}$

Answer 1

Answer: (B)

$2.4\times {10}^{-4}$

Given data,

Surface tension, $T=0.03N/m$

Surface area, $\Delta A=40c{m}^2$

Work done, $W=?$

In case of soap bubble:

$W=T\times 2\times \Delta A$

$=0.03\times 2\times 40\times {10}^{-4}$

$=2.4\times {10}^{-4}$