Question 119: Properties of Matter

Question

Two spherical soap bubbles of radii r1 and r2 in vacuum combine under isothermal conditions. The resulting bubble has a radius equal to :

Accepted Answer

no. of moles is conserved
n
1
+ n
2
= n
3
P
1
V
1
+ P
2
V
2
= P
3
V
$${{4S} \over {{r_1}}}\left( {{4 \over 3}\pi r_1^3} \right) + {{4S} \over {{r_2}}}\left( {{4 \over 3}\pi r_2^3} \right) = {{4S} \over {{r_3}}}\left( {{4 \over 3}\pi r_3^3} \right)$$
$$r_1^2 + r_2^2 = r_3^2$$
$${r_3} = \sqrt {r_1^2 + r_2^2} $$

Answer

$${{{r_1}{r_2}} \over {{r_1} + {r_2}}}$$

Answer

$$\sqrt {{r_1}{r_2}} $$

Answer

$$\sqrt {r_1^2 + r_2^2} $$

Answer

$${{{r_1} + {r_2}} \over 2}$$

Properties of Matter

Two spherical soap bubbles of radii r1 and r2 in vacuum combine under isothermal conditions. The resulting bubble has a radius equal to :

Choose the correct answer: