Question

what is the excees presure inside the soap buble of diameter 5cm and surface tensions is 0.28 ​

Answer 1

Explanation:

Excess pressure inside the soap bubble is 20Pa;

Pressure inside the air bubble is 1.06×105Pa

Soap bubble is of radius, r=5.00mm=5×10−3m

Surface tension of the soap solution, S=2.50×10−2Nm−1

Relative density of the soap solution =1.20

∴ Density of the soap solution, ρ=1.2×103kg/m3

Air bubble formed at a depth, h=40cm=0.4m

Radius of the air bubble, r=5mm=5×10−3m

1 atmospheric pressure =1.01×105Pa

Acceleration due to gravity, g=9.8m/s2

Hence, the excess pressure inside the soap bubble is given by the relation:

P=r4S

     =5×10−34×2.5×10−2

     =20Pa

Therefore, the excess pressure inside the soap bubble is 20 Pa.

The excess pressure inside the air bubble is given by the relation:

P′=r2S

       =(5×10−3)2×2.5×10−2

        =10Pa

Therefore, the excess pressure inside the air bubble is 10 Pa.

At a depth of 0.4 m, the total pressure inside the air bubble

= Atmospheric pressure +hρg+P’

=1.01×105+0.4×1.2×10