Question

The amount of work done in forming a soap film of
size 5 cm x 15 cm if surface tension is 10^-2 N/m​

Answer 1

Answer:

36 * 10^-6 Joule

Explanation:

Generally

Work = Force * Displacement OR

Work = Surface Tension * Change in Surface Area

But a bubble has two surfaces- the outer and inner Surface, hence

change in Surface Area will be 2 (5 - 2 ) = 2 * 3 cm² = 6 cm²

Work = 0.06 N/m * 6 cm² = 0.06 N/m * 6 (10^-2)² m².

Work = 36 * 10^-6 Joule