Question

Calculate the work done in blowing a soap bubble of diameter 0.6 cm against the surface tension force. (Surface tension of soap solution = 2.5 × 10⁻² N m⁻¹)

Answer 1

We know that a bubble has two surfaces in contact with air, so the total surface area of the bubble will be
=2×(4πR²)=8πR²
Now, work done=Surface tension × Increase in surface area=
2.5x10^-2 ×(8πR²−0)= 5.652x10^-2J
OR 0.056J

Answer 2

We know that a bubble has two surfaces in contact with air, so the total surface area of the bubble will be

=2×(4πR²)=8πR²

Now, work done=Surface tension × Increase in surface area=

2.5x10^-2 ×(8πR²−0)= 5.652x10^-2J

OR 0.056J