Find the work done in increasing the volume of a soap bubble by 700 % if its radius is R and surface tension is T.

Question

Find the work done in increasing the volume of a soap bubble by 700 % if its radius is R and surface tension is T. (A) 24 π R 2 T (B) 12 π R 2 T (C) 6 π R 2 T (D) π R 2 T

Tardigrade Admin · Accepted Answer

W.D. =2 × 4 π T ( r 22- r 12) If initial volume = V then final volume =8 V then radius will become 2 R So W.D. =2 × 4 π T ((2 R )2- R 2) =24 π R 2 T

Q. Find the work done in increasing the volume of a soap bubble by $700%$ if its radius is $R$ and surface tension is $T$ .

$24 π R^{2} T$

$12 π R^{2} T$

$6 π R^{2} T$

$π R^{2} T$

W.D. $= 2 \times 4 π T (r_{2}^{2} - r_{1}^{2})$
If initial volume $= V$
then final volume $= 8 V$ then radius will become $2 R$
So W.D. $= 2 \times 4 π T ((2 R)^{2} - R^{2})$
$= 24 π R^{2} T$

Q. Find the work done in increasing the volume of a soap bubble by 700% if its radius is R and surface tension is T.

24πR2T

12πR2T

6πR2T

πR2T