Question

Calculate the work done in blowing a soap bubble of diameter 0.6cm against the surface tension force.

Answer 1

Work is Force times distance.

So its pretty obvious that the work done in expanding a soap bubble is equal to the surface tension by the area, because this gives the right units:

E = N * m = N/m * m^2

E = 0.06 N/m * xm^2

Where x is the change in surface area.

So work out the area of 2 cm bubble in square metres, same for the 5 cm bubble, subtract them to find the change in surface area, then multiply by 0.06

Answer 2

HEYA MATE HERE U GO.

Given surface tension S =》2.5 × 10^-2 Nm^-1

Diameter of at soap bubble ==> 0.6cm = 0.6 × 10^-2m

Radius of soap bubble r = 0.3 × 10^-2m.

workdone W = 8phi r square S = 8× 3.14× (0.3× 10^-2)square × 2.5 × 10^-2 = 5.652 × 10-^6 joule.