Question

A soap bubble of radius R has formed at normal temperature and pressure under isothermal conditions. Complete the work done. The surface tension of soap solution is T.

Answer 1

$\huge\underline{\underline{\bf \orange{Question-}}}$

A soap bubble of radius R has formed at normal temperature and pressure under isothermal conditions. Complete the work done. The surface tension of soap solution is T.

$\huge\underline{\underline{\bf \orange{Solution-}}}$

$\large\underline{\underline{\sf Given:}}$

• Radius of soap bubble = R
• Surface tension = T

$\large\underline{\underline{\sf To\:Find:}}$

• Work done (W).

❏$\large{\boxed{\bf \blue{Work=T\triangle A} }}$

Now , we know that soap bubble have two surface , therefore ⎯

$\implies{\sf \triangle A = 2(4πR^2)}$

$\implies{\sf W = T × 2×(4πR^2)}$

$\implies{\bf \red{Work\:Done(W )= 8πR^2T}}$

$\huge\underline{\underline{\bf \orange{Answer-}}}$

Work done is ${\bf \red{8πR^2T}}$.

Answer 2

Hence the surface tension of the soap solution is W = T(8πR^2)

Explanation:

As we know that:

Work done "W" = T(ΔA)

ΔA = (4πR^2)

Soap bubble has two free surfaces.

Therefore the complete work done ca be written as:

W = T(8πR^2)

Hence the surface tension of the soap solution is W = T(8πR^2)