Question

two soap bubbles in vacuum having radii 3cm and 4cm respectively coalesce under isothermal conditions to form a single bubble. What is the radius of the new bubble?

Answer 1

two soap bubbles in vacuum having radii 3cm and 4cm respectively coalesce under isothermal conditions to form a single bubble. What is the radius of the new bubble?

Answer 2

Hey buddy,

◆ Answer-

r = 12 cm

◆ Explaination-

Lets consider, two soap bubbles with radius r1 = 4ncm nad r2 = 3 cm.

For bubble 1 -

P1 - P0 = 4T/r1

P1 = P0 + 4T/4 ...(1)

For bubble 2 -

P2 - P0 = 4T/r2

P2 = P0 + 4T/3 ...(2)

Let's, consider two bubbles merge so that-

P2 - P1 = 4T/r

P0 + 4T/3 - P0 + 4T/4 = 4T/r

4T (1/3 - 1/4) = 4T/r

1/r = 1/3 - 1/4

r = 4×3 / (4-1)

r = 12 cm

Radius of the common bubble is 12 cm.

Hope this helps you...