Question

Work done in blowing a soap bubble of radius $10cm$ is (surface tension of soap solution is $\frac{3}{100}N/m$):

• A. $75.39\times {10}^{-4}J$
• B. $37.69\times {10}^{-4}J$
• C. $150.78\times {10}^{-4}J$
  
• D. $75.39J$

Answer 1

The correct option is A $75.39\times {10}^{-4}J$

Work Done = (Surface Tension) x (increase in surface area)

Total Work done$=2\times 4\pi (\frac{10}{100}{)}^2\times \frac{3}{100}$

$=75.39\times {10}^{-4}J.$

We have to do a work of $75.39\times {10}^{-4}J$ to blow a soap bubble.