Question

What should be the pressure inside a small air bubble of 0.1 mm radius situated just below the surface of water? Surface tension of water = 7.2×10 N/m and atmospheric pressure = 1013×10¹ N/m ²​

Answer 1

Answer:

The pressure inside a small air bubble of radius 0.1mm situated just below the surface of water will be equal to [Take surface tension of water 70xx10^-3Nm^-1 and atmospheric pressure=1.013xx10^5Nm^-2]

Answer 2

Given that,

Radius of air bubble r=0.1mm=10

−3

m

Surface tension of water T=72×10

−3

N/m

Atmospheric pressure P

atm

=1.013×10

5

N/m

2

We know that,

The excess pressure inside the air bubble is given by P

2

−P

1

=

R

2T

∴ Pressure inside the air bubble P

2

=P 1+ R2T

Substituting the values, we have P

2

=1.013×10 5 + 10 −4

2×7.2×10 −2

=1.027×10 5

N/m 2