Question

A spherical bubble of radius 0.001 m is blown in an atmosphere whose

pressure is 105 N−2

. If the surface tension of the liquid comprising the

film is 0.05 N−1

, to what pressure must be the surrounding atmosphere

be brought in order that the radius of the bubble may be doubled?​

Answer 1

Answer:

Excess pressure =

R

4T

,

Gauge pressure = ρgZ

0

Now,

P

0

+

R

4T

=P

0

+ρgZ

0

Z

0

=

R×ρg

4T

Z

0

=

10

−3

×1000×10

4×2.5×10

−2

⟹Z

0

=1cm