# A soap bubble is blown to a radius of 3 cm. If it is to be further blown to a radius of 4 cm what is the work done ?

Q: A soap bubble is blown to a radius of 3 cm. If it is to be further blown to a radius of 4 cm what is the work done ?
(Surface tension of soap solution = 3.06 × 10-2 N/m

Sol: Initial radius of soap bubble R1 = 3cm = 3 × 10-2 m

Final radius of soap bubble R2 = 4cm = 4× 10-2 m

Work done in blowing soap bubble from radius R1 to R2 is

W = 8π (R22-R12) T

= 8 × 22/7 × 3.06 × 10-2 (16 – 9) × 10-4

= 176 × 3.06 × 10-6 J

= 539.6 × 10-6 J