Question

the radius of a soap bubble is 1mm and surface tension 0.03N/m.Find the energy required to increase it's radius to 2mm
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Answer 1

Explanation:

Given : Depth of air bubble below the water surface h=10cm=0.1m

Radius of air bubble R=1mm=0.001m

Surface tension of water S=0.075N/m

Excess pressure inside the air bubble ΔP=ρgh+

R

2S

∴ ΔP=1000×9.8(0.1)+

0.001

2(0.075)

=1130N/m

2