Question

Derive the formula for excess pressure inside the bubble in case of bubble in air

Answer 1

Answer:

We know that

• Force due to surface tension: F=TL  

=T(2πR)   (1)

• Force due to excess pressure on each cross section of air bubble

• F=PA   =P(πR2)   (2)

• Expression for excess pressure in air bubble

Equate the expressions (1) and (2)

• P(πR2)  = T(2πR)

• P=2T/R