Question

If the surface tension of soap solution is `35"dynes"//cm`, calculate the work done to form an air bubble of diameter 14 mm with that solution.

Answer 1

Surface tension`T=35`dynes `cm^(-1)=0.035Nm^(-1)`
`r=(14mm)/(2)=7mm=7xx10^(-3)m`
`W=DeltaA xxT=8pir^(2)T=8xx(22)/(7)xx49xx10^(-6)xx0.035`
`W=4.312xx10^(-5)J`